CVE-2026-61642 Squid - HTTP Request Smuggling

Squid 3.3.0.1 to before 7.6 contains an HTTP Request Smuggling vulnerability caused by improper enforcement of Transfer-Encoding header parsing in src/HttpHeader.cc, letting trusted clients bypass security and poison caches, exploit requires trusted client access.

CVSS base score 7.7 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
EPSS
4.68% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
HTTP Request Smuggling
Impact
Web Cache Poisoning
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
Published
13 October 2026
Updated
15 October 2026
Weakness
CWE-444

Vendor fix

Upgrade to version 7.6 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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