cross-proxy Digest auth state leak

Successfully using libcurl to do a transfer over a specific HTTP proxy proxyA with Digest authentication and then changing the proxy host to a second one proxyB for a second transfer, reusing the same handle, makes libcurl wrongly pass on the Proxy-Authorization: header field meant for proxyA, to...

CURL-CVE-2026-7168 cross-proxy Digest auth state leak

Successfully using libcurl to do a transfer over a specific HTTP proxy proxyA with Digest authentication and then changing the proxy host to a second one proxyB for a second transfer, reusing the same handle, makes libcurl wrongly pass on the Proxy-Authorization: header field meant for proxyA, to...

CURL-CVE-2026-6429 netrc credential leak with reused proxy connection

When asked to both use a .netrc file for credentials and to follow HTTP redirects, libcurl could leak the password used for the first host to the followed-to host under certain circumstances...

netrc credential leak with reused proxy connection

When asked to both use a .netrc file for credentials and to follow HTTP redirects, libcurl could leak the password used for the first host to the followed-to host under certain circumstances...

stale custom cookie host causes cookie leak

Using libcurl, when a custom Host: header is first set for an HTTP request and a second request is subsequently done using the same easy handle but without the custom Host: header set, the second request would use stale information and pass on cookies meant for the first host in the second reques...

CURL-CVE-2026-6276 stale custom cookie host causes cookie leak

Using libcurl, when a custom Host: header is first set for an HTTP request and a second request is subsequently done using the same easy handle but without the custom Host: header set, the second request would use stale information and pass on cookies meant for the first host in the second reques...

PT-2026-35895

Name of the Vulnerable Software and Affected Versions curl affected versions not specified Description When using libcurl, a flaw exists where a custom Host: header set for an initial HTTP request can cause subsequent requests using the same easy handle to use stale information. If the second...

PT-2026-35893

Name of the Vulnerable Software and Affected Versions libcurl affected versions not specified Description A logical error in the connection pooling mechanism may cause libcurl to reuse an incorrect connection for SMBS transfers. When reusing a connection, specific criteria must be met; however, a...

Insertion of Sensitive Information Into Sent Data

Overview Affected versions of this package are vulnerable to Insertion of Sensitive Information Into Sent Data via the reuse of a proxy connection during HTTP redirects when using .netrc for credentials. An attacker can obtain sensitive credential information by intercepting traffic if both the...

curl: CVE-2026-7168: cross-proxy Digest auth state leak

Summary: On libcurl 8.19.0, Proxy Digest state learned from proxyA survives an independent transfer boundary on a reused easy handle and is emitted preemptively to proxyB when the proxy is changed. In the attached C PoC, the first CONNECT to proxyB carries Proxy-Authorization: Digest ... built fr...

curl: libcurl reuses a learned RTSP Session header across different hosts on the same easy handle, enabling cross-host session leak and replay

Summary: libcurl automatically learns RTSP Session: headers from server responses and stores them in data-set.strSTRINGRTSPSESSIONID in lib/rtsp.c:1015-1033. On later RTSP requests using the same easy handle, rtspdo reads that easy-handle-scoped value at lib/rtsp.c:373 and unconditionally emits...

The vulnerability of the libcurl library in software tools for interacting with servers via cURL allows a hacker to induce a service failure.

The vulnerability of the libcurl library in software applications for interacting with servers via cURL is related to improper verification of certificate authenticity. Exploiting this vulnerability can allow an attacker to cause service failures...

curl: libssh key passphrase bypass without agent set

A flaw was found in libcurl. When doing SSH-based transfers using either SCP or SFTP, and asked to do public key authentication, curl would wrongly still ask and authenticate using a locally running SSH agent...

curl: libcurl: Improper certificate validation due to cached TLS settings reuse

A flaw was found in libcurl. When handling secure connections TLS and reusing connection settings, libcurl could incorrectly apply a cached security setting related to certificate chain validation. This could allow libcurl to accept a server's security certificate that it should have otherwise...

Moderate: Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

An update for Red Hat Hardened Images RPMs is now available. This update includes the following RPMs: curl: curl-8.19.0-3.hum1 aarch64, x8664 libcurl-8.19.0-3.hum1 aarch64, x8664 libcurl-devel-8.19.0-3.hum1 aarch64, x8664 libcurl-minimal-8.19.0-3.hum1 aarch64, x8664 curl-8.19.0-3.hum1.src source...

CVE-2026-33752 Redirect-based SSRF leading to internal network access in curl_cffi (with TLS impersonation bypass)

curlcffi is the a Python binding for curl. Prior to 0.15.0, curlcffi does not restrict requests to internal IP ranges, and follows redirects automatically via the underlying libcurl. Because of this, an attacker-controlled URL can redirect requests to internal services such as cloud metadata...

curl_cffi: Redirect-based SSRF leads to internal network access in curl_cffi (with TLS impersonation bypass)

Summary curlcffi does not restrict requests to internal IP ranges, and follows redirects automatically via the underlying libcurl. Because of this, an attacker-controlled URL can redirect requests to internal services such as cloud metadata endpoints. In addition, curlcffi’s TLS impersonation...

curl: ignoring 'options' when doing connection reuse

libcurl contains a significant logic flaw in its connection pool matching mechanism. When a transfer specifies a required authentication policy—such as a specific SASL mechanism e.g., ;AUTH=GSSAPI or a restricted set of SSH authentication types CURLOPTSSHAUTHTYPES—libcurl fails to verify these...

curl: # SCURLOPT_SSH_KNOWNHOSTS and host fingerprint pins are silently bypassed when an SSH connection is reused from the connection pool

Product libcurl all versions, all platforms, compiled with USESSH Protocols affected: sftp://, scp:// --- Summary libcurl's connection pool reuse logic for SSH-based protocols SFTP, SCP contains a security gap that allows a transfer's server-verification policy to be completely ignored. When an...

curl: Bypassing Strict SSH Server Verification via Connection Pool Reuse in libcurl

Summary There is a logic flaw in how libcurl manages its connection pool for SSH protocols SFTP/SCP. When evaluating an existing connection for reuse, sshconfigmatches in lib/url.c fails to compare server identity verification policies. By ignoring CURLOPTSSHKNOWNHOSTS, CURLOPTSSHHOSTPUBLICKEYMD5...