PT-2026-51739

Name of the Vulnerable Software and Affected Versions libcurl affected versions not specified Description A use-after-free issue exists in libcurl involving the HTTP/2 stream-dependency tree management. This occurs when an application configures the tree using CURLOPT STREAM DEPENDS or CURLOPT...

curl: CVE-2026-9080: UAF after pause in socket callback

Hi all, We've found a heap-use-after-free in lib/multiev.c triggered by calling curleasypause from within a CURLMOPTSOCKETFUNCTION callback. ASAN-confirmed with the self-contained reproducer below. Affected versions: 8.13.0 – 8.20.0 current. The entry-action write line 280 has been vulnerable sin...

curl: libcurl: Information disclosure via incorrect Proxy-Authorization header reuse

A flaw was found in libcurl. When a user performs a transfer over an HTTP proxy using Digest authentication and then reuses the same handle for a second transfer with a different proxy host, libcurl incorrectly sends the Proxy-Authorization header intended for the first proxy to the second proxy...

curl: CVE-2026-8927: env-set cross-proxy Digest auth state leak

AI-assisted preparation note I used AI assistance to help structure and format this report, but the technical findings, PoC, and verification results are based on local testing against curl/libcurl 8.20.0. Summary I found a possible incomplete-fix variant of CVE-2026-7168 in libcurl 8.20.0. The...

Amazon Linux 2023 : curl, curl-minimal, libcurl (ALAS2023-2026-1699)

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-1699 advisory. When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory. CVE-2026-3805 Tenable has extracted the preceding description block...

EUVD-2026-29923

libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTPS request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid...

CVE-2026-7168

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...

CVE-2026-6429

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...

AZL-86688 CVE-2026-6429 affecting package cmake for versions less than 3.30.3-14

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...

ALPINE-CVE-2026-6276

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...

AZL-86679 CVE-2026-6276 affecting package cmake for versions less than 3.30.3-14

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...

ALPINE-CVE-2026-6429

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...

AZL-86661 CVE-2026-6429 affecting package curl for versions less than 8.11.1-9

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...

AZL-86664 CVE-2026-5545 affecting package curl for versions less than 8.11.1-9

libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTPS request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid...

CVE-2026-6276

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...

AZL-86655 CVE-2026-6276 affecting package curl for versions less than 8.11.1-7

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...

AZL-86928 CVE-2026-5545 affecting package cmake for versions less than 3.30.3-14

libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTPS request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid...

ALPINE-CVE-2026-5773

libcurl might in some circumstances reuse the wrong connection for SMBS transfers. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the...

Improper Certificate Validation

Overview Affected versions of this package are vulnerable to Improper Certificate Validation in the OCSP stapling process with Apple SecTrust. An attacker can cause the client to accept invalid or revoked server certificates by exploiting the failure to properly detect OCSP response problems. Not...

Replay Attack

Overview Affected versions of this package are vulnerable to Replay Attack in the Proxy-Authorization: header handling process. An attacker can gain unauthorized access to resources or sensitive information by leveraging a scenario where authentication credentials intended for one proxy are...