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CVE-2026-55767

Guzzle: Dot-Only Cookie Domains Match All Hosts in guzzlehttp/guzzle

Published: Jun 23, 2026Updated: Jun 26, 2026 Sources: CVE List NVDCWE-346
5.8MEDIUM
NVD MITRE
EPSS Score
0.1%
Top 98.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
OpenVAS

Description

Guzzle is an extensible PHP HTTP client. Prior to 7.12.1, CookieJar incorrectly accepts cookies with a dot-only Domain attribute and whitespace-padded variants. SetCookie::matchesDomain() removes leading dots from the cookie domain, normalizing dot-only values to the empty string; SetCookie::validate() only rejected a strictly empty domain, so these cookies could be stored and the empty normalized domain was treated as matching any request host. An attacker-controlled origin that an application requests with a shared cookie jar can therefore set a cookie that Guzzle later sends to unrelated hosts using the same jar. This may allow cookie injection or session fixation against downstream services, depending on how those services interpret the injected cookie. This vulnerability is fixed in 7.12.1.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:CC:NI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:NConfidentiality
None
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-346CWE-1286

Affected Products

guzzle
oss-projectaka guzzlehttp/guzzle, guzzlehttp
guzzleLibrary
OSS Libraries / generic-library
guzzlephp
oss-projectaka guzzle
guzzleLibrary
OSS Libraries / generic-library

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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References

https://github.com/guzzle/guzzle/security/advisories/GHSA-cwxw-98qj-8qjx
github.com

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