CVE-2026-55767

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.21% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 11.3% of scored records. A rank, not a probability.

NVD base score

5.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

NVD analysis status

Modified. NVD last modified this record on 2026-08-05.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-06-23 15:05Z4 MO AGO

Last updated

2026-08-05 21:50Z2 MO AGO

Reserved

2026-06-17

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Medium (CVSS 5.8)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Weaknesses

• CWE-346Origin Validation ErrorClass
• CWE-1286Improper Validation of Syntactic Correctness of InputBase

Data version

5.2

Document digest

49d118d2baab625a96c9977203894c73bcd4926d4c51b4448de816a573af5764

• github.comhttps://github.com/guzzle/guzzle/security/advisories/GHSA-cwxw-98qj-8qjxx_refsource_CONFIRM
• github.comhttps://github.com/guzzle/guzzle/pull/3653x_refsource_MISC
• github.comhttps://github.com/guzzle/guzzle/commit/7f537cded1912349abf5081258d6db19106d774dx_refsource_MISC
• github.comhttps://github.com/FriendsOfPHP/security-advisories/blob/master/guzzlehttp/guzzle/CVE-2026-55767.yamlx_refsource_MISC
• github.comhttps://github.com/guzzle/guzzle/releases/tag/7.12.1x_refsource_MISC