CarrierWave has a denylisted_content_type bypass via Unescaped Regex Metacharacters

Summary CarrierWave's contenttypedenylist check fails to escape regex metacharacters in string entries, causing the denylist to silently not match the content types it is intended to block. Note: CarrierWave is aware contenttypedenylist is deprecated for the security reason, but it still used by...

CVE-2026-46727 - Use-after-free in pthread-based getaddrinfo timeout handler

SUMMARY A race condition leading to a use-after-free in the pthread-based getaddrinfo timeout handler rbgetaddrinfo in ext/socket/raddrinfo.c allows a remote attacker who can delay DNS responses near the user-specified timeout to crash a Ruby process that calls Addrinfo.getaddrinfo..., timeout: o...

Faraday has a possible incomplete fix for GHSA-33mh-2634-fwr2 - protocol-relative URI objects still bypass host scoping

Summary Faraday::Connectionbuildexclusiveurl still allows protocol-relative host override when the request target is provided as a URI object instead of a String. This bypasses the February 2026 fix for GHSA-33mh-2634-fwr2 and can redirect a request built from a fixed-base Faraday::Connection to ...

ruby-jwt: Empty-key HMAC bypass; cross-language sibling of CVE-2026-44351

JWT.decodetoken, '', true, algorithm: 'HS256' accepts an attacker-forged token. OpenSSL::HMAC.digest'SHA256', '', payload returns a valid digest under an empty key, and no raise InvalidKeyError if key.empty? precondition exists in the HMAC algorithm. JWT.decodetoken, "", true, algorithm: 'HS256' ...

Devise has an Open Redirect via Unvalidated `request.referrer` in Timeoutable Session Timeout Handler

Summary When the Timeoutable module is enabled in Devise, the FailureAppredirecturl method returns request.referrer — the HTTP Referer header, which is attacker-controllable — without validation for any non-GET request that results in a session timeout. An attacker who hosts a page with an...

view_component - Preview Route Can Dispatch Inherited Helper Methods'

The preview route derives an example name from the URL and calls it with publicsend. The code does not verify that the requested method is one of the preview examples explicitly defined by the preview class. As a result, inherited public methods on ViewComponent::Preview are route-reachable. The...

view_component - System Test Entry Point Path Check Allows Sibling Directory Escape

The system test entrypoint canonicalizes a user-controlled file path with File.realpath, then checks whether the resolved path starts with the temp directory path. This is not a safe containment check because sibling directories can share the same string prefix. Severity: Medium; test-route scope...

Sidekiq-cron is vulnerable to a cross-site scripting (xss) vulnerability via crafted URL

Sidekiq-cron thru 2.3.1, an open-source scheduling add-on for Sidekiq, is vulnerable to a cross-site scripting xss vulnerability via crafted URL being rended from cron.erb...

Session cookies can be replayed after user logout

Impact Admin session cookies were not invalidated when an admin user logged out. An attacker with access to a valid admin session cookie could continue to access admin functionality after logout, until the cookie expired or session secrets were rotated. This affects applications using Koi admin...

Improper Certificate Validation allows MITM injection of remote CSS content

Summary The CSS Parser gem does not validate HTTPS connections, allowing a Man-in-the-Middle MITM attacker to inject or modify CSS content when stylesheets are loaded via HTTPS. The connection is established with OpenSSL::SSL::VERIFYNONE, meaning any HTTPS certificate—even entirely untrusted—will...

net-imap vulnerable to denial of service via high iteration count for `SCRAM-*` authentication

Summary When authenticating a connection with SCRAM-SHA1 or SCRAM-SHA256, a hostile server can perform a computational denial-of-service attack on the client process by sending a big iteration count value. Details A hostile IMAP server can send an arbitrarily large PBKDF2 iteration count in the...

net-imap has quadratic complexity when reading response literals

Summary Net::IMAP::ResponseReader has quadratic time complexity when reading large responses containing many string literals. A hostile server can send responses which are crafted to exhaust the client's CPU for a denial of service attack. Details For each literal in a response, ResponseReader...

net-imap vulnerable to command Injection via "raw" arguments to multiple commands

Summary Several Net::IMAP commands accept a raw string argument that is sent to the server without validation or escaping. If this string is derived from user-controlled input, it may contain contain CRLF sequences, which an attacker can use to inject arbitrary IMAP commands. Details Net::IMAP's...

net-imap vulnerable to STARTTLS stripping via invalid response timing

Summary A man-in-the-middle attacker can cause Net::IMAPstarttls to return "successfully", without starting TLS. Details When using Net::IMAPstarttls to upgrade a plaintext connection to use TLS, a man-in-the-middle attacker can inject a tagged OK response with an easily predictable tag. By sendi...

net-imap vulnerable to command Injection via unvalidated Symbol inputs

Summary Symbol arguments to commands are vulnerable to a CRLF Injection / IMAP Command injection via Symbol arguments passed to IMAP commands. Details Symbol arguments represent IMAP "system flags", which are formatted as "atoms" with no quoting with a "" prefix. Vulnerable versions of Net::IMAP...

Broken Access Control Through Unauthorized Execution of Arbitrary Action Classes Across Resources

Summary A critical Broken Access Control vulnerability was identified in the ActionsController of the Avo framework v3.x. Due to insecure action lookup logic, an authenticated user can execute any Action class descendants of Avo::BaseAction on any resource, even if the action is not registered fo...

OpenC3 COSMOS has SQL Injection in QuestDB Time-Series Database

Vulnerability Type: CWE-89: Improper Neutralization of Special Elements used in an SQL Command 'SQL Injection' Attack type: Authenticated remote Impact: Telemetry data disclosure and deletion Affected components: openc3-tsdb QuestDB A SQL injection vulnerability exists in the Time-Series Database...

OpenC3 COSMOS is Vulnerable to Self-XSS Through the Command Sender

Summary The Command Sender UI uses an unsafe eval function on array-like command parameters, which allows a user-supplied payload to execute in the browser when sending a command. This creates a self-XSS risk because an attacker can trigger their own script execution in the victim’s session, if...

OpenC3 COSMOS - Hijacked session token can be used to reset password for persistence

Summary The OpenC3 password change functionality allows a user to change their password without providing the old password, by accepting a valid session token instead. In assumed breach scenarios, this behaviour can be exploited by an attacker who has already obtained a valid session token, to ga...

OpenC3 COSMOS allows arbitrary writes to plugins directory via path-traversed config filenames

Summary OpenC3 COSMOS contains a design flaw in the savetoolconfig function that allows saving tool configuration files at arbitrary locations inside the shared /plugins directory tree by supplying crafted configuration filenames. Although the implementation sufficiently mitigates standard path...

ERB has an @_init deserialization guard bypass via def_module / def_method / def_class

ERB implements an @init guard to prevent code execution when ERB objects are reconstructed via Marshal.load on untrusted data. However, ERBdefmethod, ERBdefmodule, and ERBdefclass evaluate the template source without checking this guard, allowing an attacker who controls the data passed to...

Possible arbitrary path traversal and file access via yard server

Impact A path traversal vulnerability was discovered in YARD = 0.9.41 when using yard server to serve documentation. This bug would allow unsanitized HTTP requests to access arbitrary files on the machine of a yard server host under certain conditions. The original patch in GHSA-xfhh-rx56-rxcr wa...

Decidim's comments API allows access to all commentable resources

Impact The root level commentable field in the API allows access to all commentable resources within the platform, without any permission checks. All Decidim instances are impacted that have not secured the /api endpoint. The /api endpoint is publicly available with the default configuration...

Uncontrolled resource consumption and loop with unreachable exit condition in facil.io and downstream iodine ruby gem

Summary fiojsonparse can enter an infinite loop when it encounters a nested JSON value starting with i or I. The process spins in user space and pegs one CPU core at 100 instead of returning a parse error. Because iodine gem vendors the same parser code, the issue also affects iodine gem when it...

Decidim's comments API allows access to all commentable resources

Impact The root level commentable field in the API allows access to all commentable resources within the platform, without any permission checks. All Decidim instances are impacted that have not secured the /api endpoint. The /api endpoint is publicly available with the default configuration...

Decidim amendments can be accepted or rejected by anyone

Impact The vulnerability allows any registered and authenticated user to accept or reject any amendments. The impact is on any users who have created proposals where the amendments feature is enabled. This also elevates the user accepting the amendment as the author of the original proposal as...

ERB has an @_init deserialization guard bypass via def_module / def_method / def_class

ERB implements an @init guard to prevent code execution when ERB objects are reconstructed via Marshal.load on untrusted data. However, ERBdefmethod, ERBdefmodule, and ERBdefclass evaluate the template source without checking this guard, allowing an attacker who controls the data passed to...

Decidim has a cross-site scripting (XSS) in user name

Impact A stored code execution vulnerability in the user name field allows a low-privileged attacker to execute arbitrary code in the context of any user who passively visits a comment page, resulting in high confidentiality and integrity impact across security boundaries. Patches N/A Workarounds...

bsv-sdk and bsv-wallet persist unverified certifier signatures in acquire_certificate (direct and issuance paths)

Unverified certifier signatures persisted by acquirecertificate Affected packages Both bsv-sdk and bsv-wallet are published from the sgbett/bsv-ruby-sdk repository. The vulnerable code lives in lib/bsv/walletinterface/walletclient.rb, which is physically shipped inside both gems the...

bsv-sdk and bsv-wallet persist unverified certifier signatures in acquire_certificate (direct and issuance paths)

Unverified certifier signatures persisted by acquirecertificate Affected packages Both bsv-sdk and bsv-wallet are published from the sgbett/bsv-ruby-sdk repository. The vulnerable code lives in lib/bsv/walletinterface/walletclient.rb, which is physically shipped inside both gems the...

bsv-sdk ARC broadcaster treats INVALID/MALFORMED/ORPHAN responses as successful broadcasts

ARC broadcaster treats failure statuses as successful broadcasts Summary BSV::Network::ARC's failure detection only recognises REJECTED and DOUBLESPENDATTEMPTED. ARC responses with txStatus values of INVALID, MALFORMED, MINEDINSTALEBLOCK, or any ORPHAN-containing extraInfo / txStatus are silently...

Rack::Session::Cookie secrets: decrypt failure fallback enables secretless session forgery and Marshal deserialization

'Rack::Session::Cookie incorrectly handles decryption failures when configured with secrets:. If cookie decryption fails, the implementation falls back to a default decoder instead of rejecting the cookie. This allows an unauthenticated attacker to supply a crafted session cookie that is accepted...

Addressable has a Regular Expression Denial of Service in Addressable templates

Impact Within the URI template implementation in Addressable, two classes of URI template generate regular expressions vulnerable to catastrophic backtracking: 1. Templates using the explode modifier with any expansion operator e.g., foo, +var, var, /var, .var, ;var, ?var, &var generate patterns...

rdiscount has an Out-of-bounds Read

Summary A signed length truncation bug causes an out-of-bounds read in the default Markdown parse path. Inputs larger than INTMAX are truncated to a signed int before entering the native parser, allowing the parser to read past the end of the supplied buffer and crash the process. Details In both...

Rack::Request accepts invalid Host characters, enabling host allowlist bypass

Summary Rack::Request parses the Host header using an AUTHORITY regular expression that accepts characters not permitted in RFC-compliant hostnames, including /, ?, , and @. Because req.host returns the full parsed value, applications that validate hosts using naive prefix or suffix checks can be...

Rack - Forwarded Header semicolon injection enables Host and Scheme spoofing

Summary Rack::Utils.forwardedvalues parses the RFC 7239 Forwarded header by splitting on semicolons before handling quoted-string values. Because quoted values may legally contain semicolons, a header such as: http Forwarded: for="127.0.0.1;host=evil.com;proto=https" can be interpreted by Rack as...

Rack's multipart header parsing allows Denial of Service via escape-heavy quoted parameters

Summary Rack::Multipart::Parserhandlemimehead parses quoted multipart parameters such as Content-Disposition: form-data; name="..." using repeated Stringindex searches combined with Stringslice! prefix deletion. For escape-heavy quoted values, this causes super-linear processing. An unauthenticat...

Rack::Static prefix matching can expose unintended files under the static root

Summary Rack::Static determines whether a request should be served as a static file using a simple string prefix check. When configured with URL prefixes such as "/css", it matches any request path that begins with that string, including unrelated paths such as "/css-config.env" or...

Rack::Sendfile header-based X-Accel-Mapping regex injection enables unauthorized X-Accel-Redirect

Summary Rack::Sendfilemapaccelpath interpolates the value of the X-Accel-Mapping request header directly into a regular expression when rewriting file paths for X-Accel-Redirect. Because the header value is not escaped, an attacker who can supply X-Accel-Mapping to the backend can inject regex...

Rack's improper unfolding of folded multipart headers preserves CRLF in parsed parameter values

Summary Rack::Multipart::Parser unfolds folded multipart part headers incorrectly. When a multipart header contains an obs-fold sequence, Rack preserves the embedded CRLF in parsed parameter values such as filename or name instead of removing the folded line break during unfolding. As a result,...

Rack's multipart parsing without Content-Length header allows unbounded chunked file uploads

Summary Rack::Multipart::Parser only wraps the request body in a BoundedIO when CONTENTLENGTH is present. When a multipart/form-data request is sent without a Content-Length header, such as with HTTP chunked transfer encoding, multipart parsing continues until end-of-stream with no total size...

Rack has a root directory disclosure via unescaped regex interpolation in Rack::Directory

Summary Rack::Directory interpolates the configured root path directly into a regular expression when deriving the displayed directory path. If root contains regex metacharacters such as +, , or ., the prefix stripping can fail and the generated directory listing may expose the full filesystem pa...

Rack:: Static header_rules bypass via URL-encoded paths

Summary Rack::Staticapplicablerules evaluates several headerrules types against the raw URL-encoded PATHINFO, while the underlying file-serving path is decoded before the file is served. As a result, a request for a URL-encoded variant of a static path can serve the same file without the headers...

Rack's multipart byte range processing allows denial of service via excessive overlapping ranges

Summary Rack::Utils.getbyteranges parses the HTTP Range header without limiting the number of individual byte ranges. Although the existing fix for CVE-2024-26141 rejects ranges whose total byte coverage exceeds the file size, it does not restrict the count of ranges. An attacker can supply many...

Rack's greedy multipart boundary parsing can cause parser differentials and WAF bypass.

Summary Rack::Multipart::Parser extracts the boundary parameter from multipart/form-data using a greedy regular expression. When a Content-Type header contains multiple boundary parameters, Rack selects the last one rather than the first. In deployments where an upstream proxy, WAF, or intermedia...

Rack has Content-Length mismatch in Rack::Files error responses

Summary Rack::Filesfail sets the Content-Length response header using Stringsize instead of Stringbytesize. When the response body contains multibyte UTF-8 characters, the declared Content-Length is smaller than the number of bytes actually sent on the wire. Because Rack::Files reflects the...

Rack has quadratic complexity in Rack::Utils.select_best_encoding via wildcard Accept-Encoding header

Summary Rack::Utils.selectbestencoding processes Accept-Encoding values with quadratic time complexity when the header contains many wildcard entries. Because this method is used by Rack::Deflater to choose a response encoding, an unauthenticated attacker can send a single request with a crafted...

Ruby LSP has arbitrary code execution through branch setting

Summary The rubyLsp.branch VS Code workspace setting was interpolated without sanitization into a generated Gemfile, allowing arbitrary Ruby code execution when a user opens a project containing a malicious .vscode/settings.json. Other editors that support workspace setting that get automatically...

MCP Ruby SDK - Insufficient Session Binding Allows SSE Stream Hijacking via Session ID Replay

Summary The Ruby SDK's streamablehttptransport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's Server-Sent Events SSE stream and intercept all real-time data. Details Root Cause The StreamableHTTPTransport...

Rails Active Storage has a possible DoS vulnerability in proxy mode via multi-range requests

Impact Active Storage’s proxy controller does not limit the number of byte ranges in an HTTP Range header. A request with thousands of small ranges causes disproportionate CPU usage compared to a normal request for the same file, possibly resulting in a DoS vulnerability...