PYSEC-2026-3628 h2: Duplicate Host header could facilitate request smuggling

Impact h2 =4.4.0 accepts request header blocks containing more than one Host header, and forwards every Host header to the consuming application. Where the consumer downgrades HTTP/2 to HTTP/1.1, the resulting request carries two Host header lines, which is a request smuggling primitive CWE-444...

PYSEC-2026-3643 Open WebUI: Cross-user file content disclosure via request-scoped direct model knowledge metadata

Summary Open WebUI lets a client define a model inline on a chat request instead of selecting a saved workspace model. The knowledge attached to such an inline model was used as-is, without checking that the caller can read what it points at. Any authenticated user who knows another user's file i...

PYSEC-2026-3646 Open WebUI: Users denied the image-generation permission can still generate images via chat completions

Summary An authenticated user whose features.imagegeneration permission has been revoked can still make the server generate images by sending the feature flag in a chat-completion request. The chat pipeline took the client-supplied features object at face value and never re-checked the permission...

PYSEC-2026-3647 Open WebUI: DNS Rebinding SSRF Bypass

Summary Open WebUI vetted user-supplied URLs by resolving the hostname once and rejecting private, loopback and link-local addresses, then let the HTTP client resolve that hostname again at connect time. An attacker who controls the authoritative DNS for a hostname they submit can answer with a...

PYSEC-2026-3637 Open WebUI: Any authenticated user can stall a worker via a knowledge-search pattern that backtracks catastrophically

Summary The built-in knowledge search tools let a chat participant choose the pattern used to grep knowledge files. Patterns containing regex metacharacters were compiled with Python's backtracking re engine and run against every line of every reachable file, with no time limit anywhere on that...

PYSEC-2026-3650 Open WebUI: Stored XSS via unescaped KaTeX render-error fallback in rendered messages

Summary Any authenticated user can store a chat message whose math block makes KaTeX fail with a stack overflow instead of a parse error. When that happens the renderer falls back to inserting the original math source into the page as HTML rather than as text, so script in the message runs in the...

PYSEC-2026-3644 Open WebUI: Instance-wide stall via automation recurrence rules that force multi-second parsing

Summary In every affected release, automation recurrence parsing anchors minutely and hourly rules at a fixed date of 2000-01-01 and then walks forward one interval at a time to find the next run. A single FREQ=MINUTELY rule therefore enumerates roughly a quarter-century of occurrences,...

PYSEC-2026-3639 Open WebUI: Tool source code disclosed to read-only users via the tool list and get endpoints

Summary A workspace tool shared with a read grant returned its full Python source to the recipient. Any authenticated non-admin who could use a shared tool could also read its source, including any user on the instance when a tool was shared publicly. Source is meant to be a writer-only tier: the...

PYSEC-2026-3638 Open WebUI: A folder write-collaborator can permanently delete the owner's chats by deleting a shared subfolder

Summary A user granted write access to a shared chat folder could permanently delete chats and messages belonging to the folder's owner. Deleting a folder cascades into the owner's chats and the entire subfolder subtree, and the deletion handler required only write access on subfolders instead of...

PYSEC-2026-3641 Open WebUI: Same-origin XSS to account takeover via terminal file-preview iframe hardcoding allow-same-origin

Summary Any authenticated user with access to a terminal server could get script of their choosing to run in the Open WebUI origin itself. The HTML file preview rendered terminal-served files in an iframe whose sandbox always granted allow-same-origin alongside allow-scripts, and the file is serv...

PYSEC-2026-3642 Open WebUI: Unapproved accounts can open terminal sessions via a WebSocket auth path missing the role check

Summary The terminal WebSocket route authenticates its own first-message JWT instead of going through the HTTP dependency chain, and never applies the role check that getverifieduser enforces on every HTTP terminal route. An account whose role is pending, meaning registered but not approved, or...

PYSEC-2026-3645 Open WebUI: Any authenticated user can reach internal services and cloud metadata via NAT64-encoded URLs

Summary Open WebUI fetches user-supplied URLs on the server for RAG URL ingestion, URL-to-markdown conversion and web-search content retrieval, and decides whether a destination is allowed by asking whether its IP address is globally routable. That test operates on the literal IPv6 address and do...

PYSEC-2026-3635 LangGraph: Namespace prefix matching crosses segment boundaries in Postgres and SQLite stores

Summary The Postgres and SQLite stores persist hierarchical namespaces as a dot-joined string "memories", "alice" becomes memories.alice and scoped reads by matching that string with LIKE '%'. Because LIKE has no notion of the . separator, a scoped search or listnamespaces also matched sibling...

PYSEC-2026-3648 Open WebUI: Deletion of directories and file embeddings in other knowledge bases via sync cleanup

Summary A user with write access to one knowledge base could delete directories, and drop file embeddings, belonging to knowledge bases they do not control. The sync cleanup endpoint verified write access on the knowledge base named in the URL and then acted on the directory and file ids supplied...

PYSEC-2026-3649 Open WebUI: Any member with write access to a standard channel can edit or delete other members' messages

Summary On standard channels, the message update and delete handlers accepted any caller holding write access on the channel, without checking that the caller wrote the message. Write access is the same grant a member needs in order to post, so every ordinary participant in a shared channel could...

PYSEC-2026-3629 Keras: HDF5 virtual datasets can disclose local files

Keras versions up to and including 3.13.2 are vulnerable to an arbitrary HDF5 file read due to an incomplete fix for CVE-2026-1669. The vulnerability resides in the H5IOStore.verifydataset and fileeditor.py methods, which fail to check the dataset.isvirtual property of HDF5 datasets. This allows ...

PYSEC-2026-3652 Open WebUI: Account takeover via OAuth token exchange accepting tokens issued to any client

Summary The OAuth token exchange endpoint accepts a raw provider access token and validates it by calling the provider's userinfo endpoint. A userinfo endpoint reports only that a token is valid, never which OAuth client it was issued to, and the endpoint performed no audience or client check of...

PYSEC-2026-3653 Open WebUI: SSRF into internal services via unvalidated sub-resource requests in the Playwright web loader

Summary With the Playwright web loader enabled, Open WebUI opens user-submitted URLs in a real browser and validates the destination address before allowing the request. That check only ran for the top-level page request. Every other request the page issued was passed through unvalidated, so a pa...

PYSEC-2026-3634 Keras: TorchModuleWrapper can deserialize unsafe PyTorch pickle data

A vulnerability in keras-team/keras version 3.15.0 allows unsafe deserialization of attacker-controlled PyTorch pickle data through the public keras.layers.TorchModuleWrapper.fromconfig method. This method invokes torch.load..., weightsonly=False without requiring an explicit unsafe opt-in, such ...

PYSEC-2026-3630 Keras: tar extraction permits symlink-based path traversal

A vulnerability in keras-team/keras version 3.12.0 allows an attacker to craft a malicious tar archive that bypasses the filtersafetarinfos validation in keras/src/utils/fileutils.py. Specifically, symlink entries are not subjected to the same ispathindir validation as regular file entries,...

PYSEC-2026-3640 Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint

Summary DELETE /api/v1/chats/id cancelled a chat's in-flight tasks before it checked whether the caller was allowed to delete that chat. Any authenticated user who knew another user's chat id could therefore abort that user's running model response, title generation or tag generation. The deletio...

PYSEC-2026-3633 Keras: HDF5 links can disclose local file contents

A vulnerability in keras-team/keras versions = 3.14.0 allows arbitrary local HDF5 file content disclosure due to improper handling of HDF5 ExternalLinks. The KerasFileEditor and keras.saving.loadweights functions bypass the safegeth5group and safegeth5dataset helpers, which are designed to reject...

PYSEC-2026-3632 Keras: DiskIOStore permits path traversal through crafted layer names

A path traversal vulnerability exists in keras-team/keras version 3.14.0, specifically in the DiskIOStore.make method within the Keras 3 model saving and loading library. This vulnerability arises from the improper handling of user-provided layer names, which are used to construct directory paths...

PYSEC-2026-3651 Open WebUI: Client-side SSRF via unrestricted external resource loading in Vega/Vega-Lite chart rendering

Summary Open WebUI renders vega and vega-lite fenced code blocks in chat content by building a Vega view in the viewer's browser without a restricted resource loader. Any user who can place such a block where another user will see it can make that user's browser issue attacker-chosen outbound GET...

PYSEC-2026-3631 Keras: Lambda deserialization can bypass safe mode and execute code

A vulnerability in keras-team/keras version 3.14.0 allows for arbitrary code execution due to improper handling of deserialization in the Lambda layer. Specifically, the raiseforlambdadeserialization function fails to enforce the safe-mode guard when safemode is set to None, which is the default...

PYSEC-2026-3626 aiosend: Deserialization of request body before signature verification (Pre-auth DoS) in webhook handler

Summary WebhookHandler.feedupdate deserializes the entire request body before verifying the HMAC signature. This allows an unauthenticated attacker to force expensive parsing of arbitrary JSON payloads that will ultimately be rejected, leading to unnecessary CPU and memory consumption. Severity...

PYSEC-2026-3955

A Server-Side Request Forgery SSRF vulnerability exists in nltk/nltk versions 3.9.4 and the current develop branch. The nltk.pathsec.validatenetworkurl function, intended to prevent SSRF by rejecting internal network addresses, fails to reject IPs in the RFC 6598 shared address space 100.64.0.0/1...

PYSEC-2026-3954

A vulnerability in nltk.downloader in nltk/nltk versions = 3.9.4 allows for cross-package resource and model poisoning. The downloader extracts package archives into shared namespaces such as corpora/ and taggers/ instead of package-isolated roots, and validates package integrity only after the...

PYSEC-2026-3623

Apache Polaris did not consistently validate storage locations supplied during table and view registration. An authenticated principal with permission to register a table or view could, depending on the affected release and registration path, cause Polaris to use the catalog's storage credentials...

PYSEC-2026-3717

An issue was discovered in Django 5.2 before 5.2.17 and 6.0 before 6.0.8. GeoDjango's django.contrib.gis.geos.GEOSGeometry is subject to a potential denial-of-service when parsing deeply nested GEOMETRYCOLLECTION objects supplied as well-known text WKT, well-known binary WKB, or hex-encoded WKB,...

PYSEC-2026-3554 python-cryptography verifier accepts wildcard DNS names allowing escape from permittedSubtrees

Summary If an intermediate constrained CA permits the DNS name foo.example.com, and the leaf certificate has a wildcard in its DNS SAN of .example.com, python-cryptography's verifier accepts which allows escaping outside of the permitted names. PoC !/usr/bin/env python3 """Standalone PoC: pyca's...

PYSEC-2026-3552 cryptography: PKCS#7 EnvelopedData decryption exposes a Bleichenbacher oracle through distinguishable errors and timing

Summary pkcs7decryptder, pkcs7decryptpem, and pkcs7decryptsmime reported the outcome of decrypting a RecipientInfo's encryptedKey in several distinguishable ways, one of which disclosed the exact length recovered from the RSA operation. The same distinction was also observable by timing. An...

PYSEC-2026-3545 AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response)

Summary An out-of-bounds heap read could occur in the C response parser while building an error message for a malformed response. Impact An attacker controlled server, or possibly an accidental response could trigger a DoS in the client. Workaround If unable to upgrade, the Python parser is...

PYSEC-2026-3546 AIOHTTP: HTTP request smuggling via WebSocket upgrade

Summary The HTTP parsers were vulnerable to a request smuggling attack relating to WebSocket upgrades. Impact If using the server-side component, it may be possible for an attacker to execute a request smuggling vulnerability using an edge case in the WebSocket upgrade procedure. AIOHTT is unawar...

PYSEC-2026-3553 python-cryptography: Duplicate self-signed intermediates can cause exponential path-building

Summary When resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents...

PYSEC-2026-3616 Thumbor has Regex Denial of Service (ReDoS) in `convolution` filter

Summary The regular expression used to parse the convolution filter exhibits exponential-time backtracking for certain inputs, enabling a Regular Expression Denial of Service ReDoS. Details The RegExp for convolution is defined as...

PYSEC-2026-3547 AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate

Summary The client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated. Impact A client may unexpectedly decompress WebSocket frames when explicitly opted out. This could lead to additional CPU/memory consumption, but is unlikely to ...

PYSEC-2026-3582 Natural Language Toolkit (NLTK): ReDoS in NLTK ReviewsCorpusReader FEATURES regex

Summary ReviewsCorpusReader extracts feature annotations of the form label followed by a bracketed signed digit e.g. a label then +2 from each review line, using the module-level FEATURES regex. The feature-label sub-pattern is unbounded — an optional greedy run of word-plus-whitespace groups...

PYSEC-2026-3617 Thumbor treats ALLOWED_SOURCES string patterns as unescaped regex, allowing hostname bypass via wildcard dot

Summary The ALLOWEDSOURCES configuration is meant to restrict which hosts Thumbor's HTTP loader may fetch images from. Plain-string entries in that list the overwhelming majority of real-world and documented configurations are passed directly to re.match without escaping. Because . is a regex...

PYSEC-2026-3618 Thumbor has path traversal via post-validation URL decoding bypass in file_loader

The fileloader performs unquote on the file path AFTER the abspath + startswith security check. An attacker can use percent-encoded path traversal sequences %2e%2e for .. that pass the security check as literal directory names, but are then decoded to actual .. traversal sequences. Affected code...

PYSEC-2026-3619 Thumbor convolution filter allows divide-by-zero in C extension leading to remote DoS

Summary Thumbor's filters:convolution, , filter passes the user-controlled value to a C extension thumbor/ext/filters/convolution.c where it is used as a divisor for % and / without validating columns 0. When columns=0, the C code triggers undefined behavior; on x8664 this reliably results in a...

PYSEC-2026-3583 Natural Language Toolkit (NLTK): DNS-rebinding SSRF filter bypass in nltk.pathsec.urlopen (nltk.download / nltk.data.load) defeats ENFORCE mode

Summary nltk.pathsec provides an SSRF filter that NLTK documents as a security control, blocking loopback, private, link-local, and multicast ranges including obfuscated forms and recommending strict ENFORCE mode for security-sensitive environments. The filter is bypassable by DNS rebinding:...

PYSEC-2026-3574 gemini-bridge vulnerable to arbitrary local file read via consult_gemini_with_files inline mode

Summary consultgeminiwithfiles in inline mode read any file path supplied in the files argument without confining it to the working directory, then forwarded the contents to the Gemini CLI. Because the caller also controls query, the file contents are echoed back through the Gemini round-trip and...

PYSEC-2026-3621 Thumbor proportion filter allows unbounded post-transform resize leading to remote DoS

Summary Thumbor's filters:proportion filter does not enforce an upper bound on and runs in the post-transform phase. An attacker can trigger extremely large resizes CPU/memory exhaustion and cause denial of service. Details - Filter implementation: thumbor/filters/proportion.py - value is parsed ...

PYSEC-2026-3620 Thumbor has HMAC validation bypass via multiple .replace() calls when removing URL signature

HMAC validation bypass via multiple .replace calls when removing URL signature Summary Thumbor’s HMAC validation can be bypassed due to the use of Python’s .replace when removing the signature from the URL before validation. Since .replace removes all occurrences of the substring, an attacker can...

PYSEC-2026-3584 Natural Language Toolkit (NLTK) has path traversal in FramenetCorpusReader.frame() that allows arbitrary XML file read, bypassing the nltk.pathsec sandbox (ENFORCE=True)

Summary FramenetCorpusReader.framename interpolates a caller-supplied frame name into an XML file path that is read with the builtin open, bypassing CorpusReader.open and the nltk.pathsec sandbox — including strict ENFORCE=True mode. A ../ sequence in the name escapes the corpus root, yielding an...

PYSEC-2026-3578 linuxfabrik-lib: fetch() forwards credential headers across a cross-origin redirect

Summary lib.url.fetch follows HTTP redirects followredirects=True. httpx strips only Authorization and Cookie when a redirect crosses the origin, so any other caller-supplied credential header a session token such as Redfish's X-Auth-Token, an API key, ... was still sent to the redirect target. A...

PYSEC-2026-3581 Natural Language Toolkit (NLTK): Path Traversal in NKJPCorpusReader leads to Arbitrary File Read and bypasses the nltk.pathsec sandbox (ENFORCE=True)

Summary A path-traversal vulnerability in NKJPCorpusReader allows an attacker who can influence the fileids argument of its public read methods header, raw, words, sents, taggedwords to read files outside the corpus root. The reader builds the file path with no containment check and opens it with...

PYSEC-2026-3569 Flyto2 Core: Guarded HTTP modules follow redirects into internal space without per-hop SSRF revalidation

Summary The HTTP modules that DO call the SSRF guard http.get, http.request, http.batch validate only the initial URL, then issue the request with aiohttp's default allowredirects=True and perform no per-hop revalidation. An attacker hosts a public URL that 302-redirects to an internal address; t...

PYSEC-2026-3607 proot-distro has a Container Isolation Bypass via Crafted Restore Archive

Affected Component - Package: proot-distro - Affected command: restore - Attack surface: Host-side Termux CLI processing a user-supplied backup archive - Vulnerability type: Container Isolation Bypass / Cross-Container Read and Write --- Affected Versions | Component | Version | |---|---| |...