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Fencer Vulns
medium 5.5

CVE-2026-50012 json

Squid: Memory corruption in cache_digest reply handling

published 2026-07-16 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-44961

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 71%
public exploits
0
none known

Summary

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.

Patch / fix

  • squid-cache squid 7.6
  • squid Debian 12 5.7-2+deb12u6
  • squid Debian 13 6.13-2+deb13u2
  • squid Debian 14 7.6-1

debian advisories DEBIAN-CVE-2026-50012

  • squid Ubuntu 22.04 LTS 5.9-0ubuntu0.22.04.7
  • squid Ubuntu 24.04 LTS 6.14-0ubuntu0.24.04.4
  • squid Ubuntu 25.10 6.14-0ubuntu0.25.10.4
  • squid Ubuntu 26.04 LTS 7.2-2ubuntu2.2
  • squid Ubuntu Pro 20.04 LTS 4.10-1ubuntu1.13+esm3
  • squid3 Ubuntu Pro 16.04 LTS 3.5.12-1ubuntu7.16+esm7
  • squid3 Ubuntu Pro 18.04 LTS 3.5.27-1ubuntu1.14+esm6

ubuntu advisories UBUNTU-CVE-2026-50012

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • squid SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 5.7-150400.3.41.1
  • squid SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Server Applications 15 SP7 6.14-150600.3.20.1
  • squid SLES for SAP applications 16.0, SLES 16.0 6.14-160000.1.1

suse advisories SUSE-SU-2026:4909-1SUSE-SU-2026:4621-1SUSE-SU-2026:24224-1

  • squid openSUSE Leap 16.0 6.14-160000.1.1
  • squid openSUSE Tumbleweed 7.7-2.1

opensuse advisories openSUSE-SU-2026:22080-1openSUSE-SU-2026:11937-1

  • squid Alpine 3.24, Alpine 3.23 7.6-r0

alpine advisories ALPINE-CVE-2026-50012

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • squid Azure Linux 3.0 6.13-5

azure linux advisories AZL-92447

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-50012 updated cvss 5.5

squid: memory corruption in cache_digest reply handling

  • Red Hat Enterprise Linux 6 squid, squid34 Red Hat Enterprise Linux 7 squid, squid-sysvinit, squid-migration-script Red Hat Enterprise Linux 8 squid, libecap Red Hat Enterprise Linux 9 squid Red Hat Enterprise Linux 10 squid
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

1.36% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H
NVD 3.1 5.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H

Affected products

  • squid-cache squid

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-122 Heap-based Buffer Overflow

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.