Detections
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Squid 5.x < 7.7 Stack-based Buffer Overflow (SQUID-2026:7)

medium Nessus Plugin ID 377052

Synopsis

The remote proxy server is affected by a stack-based buffer overflow vulnerability.

Description

The version of Squid on the remote host is 5.x, 6.x or 7.x prior to 7.7. It is, therefore, affected by a stack-based buffer overflow vulnerability:

 - Due to an Improper Input Validation bug, Squid is vulnerable to a stack-based buffer overflow attack against HTTP authentication. This problem allows a trusted client to perform an out-of-bounds write when Squid is configured to authenticate with a peer server using client provided Basic authentication credentials. This attack is limited to Squid deployments passing client supplied Basic authentication credentials to a cache_peer. (CVE-2026-104786)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Squid version 7.7 or later, or apply the patch referenced in the vendor advisory.

See Also

http://www.nessus.org/u?63d1ba32

Plugin Details

Severity: Medium

ID: 377052

File Name: squid_2026_7.nasl

Version: 1.1

Type: Remote

Family: Firewalls

Published: 11/6/2026

Updated: 11/6/2026

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.63

CVSS v2

Risk Factor: Medium

Base Score: 5.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:P/A:P

CVSS Score Source: CVE-2026-104786

CVSS v3

Risk Factor: Medium

Base Score: 5.4

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

Vulnerability Information

CPE: cpe:/a:squid-cache:squid

Required KB Items: installed_sw/Squid, Settings/ParanoidReport

Patch Publication Date: 8/24/2026

Vulnerability Publication Date: 9/12/2026

Reference Information

CVE: CVE-2026-104786

CWE: 121, 20

IAVB: 2026-B-0322