CVE Vulnerabilities

CVE-2026-5545

Insufficient Session Expiration

Published: May 13, 2026 | Modified: May 13, 2026
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
6.5 MODERATE
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Ubuntu
MEDIUM
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libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTP(S) 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 overhead.

When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials.

An application that first uses Negotiate authentication to a server with user1:password1 and then does another operation to the same server asking for any authentication method but for user2:password2 (while the previous connection is still alive) - the second request gets confused and wrongly reuses the same connection and sends the new request over that connection thinking it uses a mix of user1s and user2s credentials when it is in fact still using the connection authenticated for user1…

Weakness

According to WASC, “Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.”

Affected Software

NameVendorStart VersionEnd Version
CurlHaxx7.10.6 (including)8.20.0 (excluding)
Red Hat Hardened ImagesRedHatcurl-main-8.20.0-0.1.hum1*
CurlUbuntudevel*
CurlUbuntuesm-infra-legacy/trusty*
CurlUbuntuesm-infra-legacy/xenial*
CurlUbuntuesm-infra/bionic*
CurlUbuntuesm-infra/focal*
CurlUbuntuesm-infra/xenial*
CurlUbuntujammy*
CurlUbuntunoble*
CurlUbuntuquesting*
CurlUbunturesolute*
CurlUbuntuupstream*

Potential Mitigations

References