Red Hat Security Advisory: squid security update

Fixed packages 4

Vulnerabilities 2

• Critical 9.3
  CVE-2025-54574 Public exploit EPSS 22%

  Squid's URN Handling can lead to Buffer Overflow

  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…

  squid-cache squid squid squid3 Debian Ubuntu Azure Linux
  Aug 1, 2025
• Unscored —
  CVE-2021-28651

  An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it allows a denial o…

  squid squid3 squid squid Debian Ubuntu Alpine
  May 27, 2021

References

• article
  https://access.redhat.com/security/updates/classification/#important
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=1962243
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=2386026
• advisory
  https://security.access.redhat.com/data/csaf/v2/advisories/2025/rhsa-2025_14414.json
• report
  https://access.redhat.com/security/cve/CVE-2021-28651
• advisory
  https://www.cve.org/CVERecord?id=CVE-2021-28651
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2021-28651
• article
  https://github.com/squid-cache/squid/security/advisories/GHSA-ch36-9jhx-phm4
• report
  https://access.redhat.com/security/cve/CVE-2025-54574
• advisory
  https://www.cve.org/CVERecord?id=CVE-2025-54574
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2025-54574
• article
  https://github.com/squid-cache/squid/commit/a27bf4b84da23594150c7a86a23435df0b35b988
• article
  https://github.com/squid-cache/squid/releases/tag/SQUID_6_4
• article
  https://github.com/squid-cache/squid/security/advisories/GHSA-w4gv-vw3f-29g3