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CVE-2025-54574
Squid's URN Handling can lead to Buffer Overflow
Critical9.3EPSS 22.1%
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical9.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:H |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 22.1% · top 2.3% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.3.
Weakness
Affected products
- affected < 6.4
References (5)
- https://github.com/squid-cache/squid/security/advisories/GHSA-w4gv-vw3f-29g3 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/squid-cache/squid/commit/a27bf4b84da23594150c7a86a23435df0b35b988 (opens in a new tab)x_refsource_MISC
- https://github.com/squid-cache/squid/releases/tag/SQUID_6_4 (opens in a new tab)x_refsource_MISC
- https://lists.debian.org/debian-lts-announce/2025/09/msg00027.html (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2025/11/05/5 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2025-54574)Record last updated .