CVE-2026-50012: Squid-Cache Squid

Medium severity, CVSS 5.5. EPSS: 2.7% chance of exploitation in the next 30 days.

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.

Affected products

• Squid-Cache Squid: before 7.6 (fixed in 7.6)

Published 2026-07-16. Last modified 2026-07-20.