Log in Start free

Vulnerability · Published Aug 3, 2026 · Assigned by GitHub_M

CVE-2026-69245Guzzle: Noncanonical cookie domain keeps subdomain scope

Medium 6.5

In plain English

A medium-severity session fixation in guzzle from guzzle. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.2%top 90.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Guzzle is an extensible PHP HTTP client. Prior to 7.15.2 and 8.0.1, SetCookie::matchesDomain() gives every subdomain of a cookie Domain that cookie unless SetCookie::matchesDomain() recognizes the Domain as an IP literal or a numeric host, and the decision comes from the domain's own text, so two spellings a transport reads as an address keep subdomain scope. Hexadecimal and mixed-base forms such as 0x7f000001 and 0177.0.0.0x1 go unrecognized while libcurl 8.21.0 reads both as 127.0.0.1. A percent-escaped Domain keeps that scope on both branches because percent-decoding sits above numeric parsing, so 192.168.0.%31 and 127.0.0.1%2e are registered names in the URI grammar rather than address literals, and no numeric rule in any base classifies them, while libcurl decodes the host before resolving and reads them as 192.168.0.1 and 127.0.0.1. A cookie stored for Domain=0x7f000001 is placed in the Cookie header of a request to evil.0x7f000001, disclosing a session identifier or token to a host that is not that address, and a response from evil.0x7f000001 setting Domain=0x7f000001 is accepted into the jar and replayed to the address, so a server answering for the look-alike name can fix a session or set application state. Exploitation requires the application to enable cookie support, address an origin by one of these spellings, and contact a host whose name ends in that spelling. This issue is fixed in versions 7.15.2 and 8.0.1.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12guzzleno fix listedDEBIAN-CVE-2026-69245
Debian:13guzzleno fix listedDEBIAN-CVE-2026-69245
Debian:14guzzle7.15.2-1DEBIAN-CVE-2026-69245
Packagistguzzlehttp/guzzle8.0.1GHSA-f7vp-7xgx-4w4r
Packagistguzzlehttp/guzzle7.15.2GHSA-f7vp-7xgx-4w4r
Ubuntu:24.04:LTSguzzleno fix listedUBUNTU-CVE-2026-69245
Ubuntu:26.04:LTSguzzleno fix listedUBUNTU-CVE-2026-69245
Ubuntu:26.10guzzleno fix listedUBUNTU-CVE-2026-69245

Affected products (as reported)

VendorProductVersions
guzzle guzzle < 7.15.2>= 8.0.0, < 8.0.1

Weakness: CWE-180, CWE-346, CWE-384 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References