CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:HSquid 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.
A 29-year-old vulnerability, dubbed Squidbleed (CVE-2026-47729), exists in the Squid web proxy due to a heap over-read. This allows an attacker with proxy access to leak cleartext HTTP requests, including credentials and…
