CVE-2025-54574Squid's URN Handling can lead to Buffer Overflow

Description

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.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• https://github.com/squid-cache/squid/security/advisories/GHSA-w4gv-vw3f-29g3 MitigationPatchVendor Advisory
• https://github.com/squid-cache/squid/commit/a27bf4b84da23594150c7a86a23435df0b35b988 Patch
• https://github.com/squid-cache/squid/releases/tag/SQUID_6_4 Release Notes
• http://www.openwall.com/lists/oss-security/2025/11/05/5
• https://lists.debian.org/debian-lts-announce/2025/09/msg00027.html