Summary
It was discovered that Squid incorrectly handled certain HTTP Transfer-
Encoding headers. An attacker could possibly use this issue to perform HTTP
request smuggling attacks, bypass security mechanisms, or poison web
caches. (CVE-2026-61642)
It was discovered that Squid incorrectly handled certain cache digest
replies, which could lead to a buffer overflow. A remote attacker could
possibly use this issue to cause Squid to crash, resulting in a denial of
service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and
Ubuntu 20.04 LTS. (CVE-2026-50012)
It was discovered that Squid incorrectly handled parsing certain FTP
directory listings. A remote attacker could possibly use this issue to
obtain sensitive information. This issue only affected Ubuntu 16.04 LTS,
Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-47729)
It was discovered that Squid incorrectly handled certain ICP traffic. A
remote attacker could possibly use this issue to cause Squid to crash,
resulting in a denial of service. This issue only affected Ubuntu 16.04
LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-32748,
CVE-2026-33526)
It was discovered that Squid incorrectly handled certain ICP requests. A
remote attacker could possibly use this issue to obtain sensitive
information. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS,
and Ubuntu 20.04 LTS. (CVE-2026-33515)
Fixed packages 5
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · 22.04 LTS 22.04:LTS | squid | 5.9-0ubuntu0.22.04.8 |
| Ubuntu · 24.04 LTS 24.04:LTS | squid | 6.14-0ubuntu0.24.04.5 |
| Ubuntu · Pro 16.04 LTS Pro:16.04:LTS | squid3 | 3.5.12-1ubuntu7.16+esm7 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | squid3 | 3.5.27-1ubuntu1.14+esm6 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | squid | 4.10-1ubuntu1.13+esm3 |
Vulnerabilities 6
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Critical 9.2
Squid vulnerable to Denial of Service in ICP Request handling
Squid is a caching proxy for the Web. Prior to version 7.5, due to heap Use-After-Free, Squid is vulnerable to Denial of Service when handling ICP traffic. This problem allows a remote attacker to perform a reliable and repeatable Denial of Service attack aga…
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High 8.7
Squid has Denial of Service in ICP Response handling
Squid is a caching proxy for the Web. Prior to version 7.5, due to premature release of resource during expected lifetime and heap Use-After-Free bugs, Squid is vulnerable to Denial of Service when handling ICP traffic. This problem allows a remote attacker t…
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High 7.7
Squid Request Smuggling in HTTP Transfer-Encoding
Squid is a caching proxy for the Web. From 3.3.0.1 to before 7.6, due to an improper enforcement of behavioral workflow bug, Squid is vulnerable to a Request Smuggling attack against HTTP/1.1 Transfer-Encoding. HTTP header parsing (`src/HttpHeader.cc`) accept…
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Medium 6.9
Squid has issues in ICP message handling
Squid is a caching proxy for the Web. Prior to version 7.5, due to improper input validation, Squid is vulnerable to out of bounds read when handling ICP traffic. This problem allows a remote attacker to receive small amounts of memory potentially containing …
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Medium 6.5CVE-2026-47729 Public exploit
Squid: Memory disclosure in FTP gateway
Squid is a caching proxy for the Web. Prior to 7.6, due to an improper validation of syntactic correctness of input in the FTP gateway (src/clients/FtpGateway.cc), Squid is vulnerable to an out-of-bounds read: when a listing entry date in the TypeA or TypeB d…
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Medium 5.5
Squid: Memory corruption in cache_digest reply handling
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…