CVE-2026-50012 Squid: Memory corruption in cache_digest reply handling
A heap-based buffer overflow in Squid allows a trusted peer to execute code or cause denial of service via malicious cache digest replies.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-50012?
CVE-2026-50012 is a medium-severity memory corruption vulnerability in Squid-Cache Squid, published on 16 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-50012?
It affects 1 product.
Products include Squid-Cache Squid.
How do I fix CVE-2026-50012?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-50012 being exploited?
There is no known exploitation of CVE-2026-50012 in the wild and no public exploit code.
Other vulnerabilities in Squid-Cache Squid
- CVE-2025-62168 Squid vulnerable to information disclosure via authentication credential leakage in error handling
- CVE-2025-54574 Squid's URN Handling can lead to Buffer Overflow
- CVE-2026-33526 Squid vulnerable to Denial of Service in ICP Request handling
- CVE-2026-32748 Squid has Denial of Service in ICP Response handling
- CVE-2023-50269 SQUID-2023:10 Denial of Service in HTTP Request parsing
Sources
Also known as ALPINE-CVE-2026-50012, AZL-92447, DEBIAN-CVE-2026-50012, GHSA-5vmx-9x64-9284, MINI-pcfw-mr37-wfhc, UBUNTU-CVE-2026-50012.