CVE-2026-50012

Publication date 12 June 2026

Last updated 7 August 2026

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
squid	26.04 LTS resolute	Fixed 7.2-2ubuntu2.2
	25.10 questing	Fixed 6.14-0ubuntu0.25.10.4
	24.04 LTS noble	Fixed 6.14-0ubuntu0.24.04.4
	22.04 LTS jammy	Fixed 5.9-0ubuntu0.22.04.7
	20.04 LTS focal	Needs evaluation
squid3	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
squid	Upstream: 19fcfe9

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.5 · Medium

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	High
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	Low
Availability impact	High

Scores

Parameter	Value
Base score	5.5 · Medium
Exploitability score	-
Impact score	-

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