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.
CVSS Details
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade squid | Jul 22, 2026 | Jul 16, 2026 |
| Amazon Linux Ami 2 | — | Upgrade squidUpgrade squid-migration-scriptUpgrade squid-debuginfoUpgrade squid-sysvinit | Jun 23, 2026 | Jun 23, 2026 |
| Amazon_linux_2023 | — | Upgrade squid-debuginfoUpgrade squid-debugsourceUpgrade squid | Jul 17, 2026 | Jul 16, 2026 |
| Debian | — | Upgrade squid | Jul 23, 2026 | Jul 23, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Jun 23, 2026 |
| Ubuntu | — | Upgrade squid | Jun 17, 2026 | Jun 16, 2026 |
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