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Vulnerability record · CVE-2026-50012 · published 16 July 2026

CVE-2026-50012: Squid-cache squid improper input validation vulnerability

Squid Cache · Squid

Squid is a caching proxy for the Web. Prior to 7.6, due to an improper input validation bug in cache digest reply handling (peerDigestSwapInMask in src/peer_digest.cc), Squid is vulnerable to a heap-based buffer overflow: a cache digest's on-the-wire size may be larger than the mask_size declared within the digest, so a trusted peer sending a maliciously crafted reply to a cache_digest request message can trigger the overflow. This attack is limited to Squid instances compiled with the --enable-cache-digests option and configured with cache_peer entries. This issue is fixed in version 7.6.

5.5 CVSS 3.1 Medium EPSS 2.7% · top 14.8% CWE-20 · Improper input validationCWE-122 · Heap-based buffer overflow
5.5CVSS 3.1 base score
2.7%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
20 Jul 2026Last modified by NVD

Description

Squid is a caching proxy for the Web. Prior to 7.6, due to an improper input validation bug in cache digest reply handling (peerDigestSwapInMask in src/peer_digest.cc), Squid is vulnerable to a heap-based buffer overflow: a cache digest's on-the-wire size may be larger than the mask_size declared within the digest, so a trusted peer sending a maliciously crafted reply to a cache_digest request message can trigger the overflow. This attack is limited to Squid instances compiled with the --enable-cache-digests option and configured with cache_peer entries. This issue is fixed in version 7.6.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/squid-cache/squid/commit/19fcfe922717c8b255270c032dcde4071c003bcd Patch
https://github.com/squid-cache/squid/pull/2423 Patch
https://github.com/squid-cache/squid/releases/tag/SQUID_7_6 Release Notes
https://github.com/squid-cache/squid/security/advisories/GHSA-5vmx-9x64-9284 Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-50012), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.