CVE-2025-54574

moderate-risk

Published 2025-08-01

Squid is a caching proxy for the Web. In versions 6.3 and below, Squid is vulnerable to a heap buffer overflow and possible remote code execution attack when processing URN due to incorrect buffer management. This has been fixed in version 6.4. To work around this issue, disable URN access permissions.

Do I need to act?

3.9% chance of exploitation in next 30 days

EPSS score — moderate exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 9.3/10 Critical

NETWORK / LOW complexity

Affected Products (1)

Squid

Affected Vendors

Squid-Cache

References (5)

Patch https://github.com/squid-cache/squid/commit/a27bf4b84da23594150c7a86a23435df0b35...

Release Notes https://github.com/squid-cache/squid/releases/tag/SQUID_6_4

Mitigation https://github.com/squid-cache/squid/security/advisories/GHSA-w4gv-vw3f-29g3

http://www.openwall.com/lists/oss-security/2025/11/05/5

https://lists.debian.org/debian-lts-announce/2025/09/msg00027.html

/ 100

moderate-risk

Severity 31/34 · Critical

Exploitability 7/34 · Low

Exposure 5/34 · Minimal