Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2026-55767

5.8 · MEDIUM

Guzzle is an extensible PHP HTTP client.

Published Jun 23, 2026CWE-346EPSS 0.21%

Overview

CVE-2026-55767 is a medium-severity vulnerability. It was published on June 23, 2026 and has a CVSS 3.1 base score of 5.8 (MEDIUM).

This vulnerability has a CVSS 3.1 base score of 5.8, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

Technical 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.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

GitHubgithub.com/FriendsOfPHP/security-advisories/blob/master/guzzlehttp/guzzle/CVE-2026-55767.yamlGitHubgithub.com/guzzle/guzzle/commit/7f537cded1912349abf5081258d6db19106d774dGitHubgithub.com/guzzle/guzzle/pull/3653GitHubgithub.com/guzzle/guzzle/releases/tag/7.12.1GitHubgithub.com/guzzle/guzzle/security/advisories/GHSA-cwxw-98qj-8qjx

How CyberStrike helps

Frequently asked questions

What is CVE-2026-55767?

CVE-2026-55767 is a medium-severity vulnerability. It was published on June 23, 2026 and has a CVSS 3.1 base score of 5.8 (MEDIUM).

How severe is CVE-2026-55767?

This vulnerability has a CVSS 3.1 base score of 5.8, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2026-55767?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-55767?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-55767 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related MEDIUM CVEs from 2026

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999