Buffer overflow in Squid-Cache Squid

CVE-2026-50012

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.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H.

EPSS exploit prediction

EPSS: 0.014 (71.6th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 71.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-50012: fell from 0.027 to 0.014.

EPSS over last 30 days · oldest: 0.027 · newest: 0.014 · change: -0.013

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-50012?
CVE-2026-50012 is a medium-severity vulnerability in Squid-Cache Squid, classified under Improper Input Validation. CVSS score: 5.5/10. Published 2026-07-16.
How severe is CVE-2026-50012?
Medium severity. CVSS v3 base score is 5.5 out of 10.