Squid < 7.6 Heap-based Buffer Overflow

critical Nessus Plugin ID 321511

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Synopsis

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

Description

The version of Squid on the remote host is prior to 7.6. It is, therefore, affected by a heap-based buffer overflow vulnerability:

- Due to an Improper Input Validation bug, Squid is vulnerable to a Heap-based Buffer Overflow attack against cache digests. This problem allows a trusted server to perform a Heap-based Buffer Overflow when sending maliciously crafted replies to cache_digest request messages. This attack is limited to Squid instances that have been compiled with the --enable-cache-digests option. (CVE-2026-50012)

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 7.6 or later.

Plugin Details

Severity: Critical

ID: 321511

File Name: squid_7_6.nasl

Version: 1.3

Type: Remote

Family: Firewalls

Published: 6/18/2026

Updated: 6/26/2026

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 7

Percentile: 98.3

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 4.7

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

CVSS Score Source: CVE-2026-50012

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

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

Required KB Items: installed_sw/Squid, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 6/8/2026

Vulnerability Publication Date: 6/12/2026

Reference Information

CVE: CVE-2026-50012

IAVB: 2026-B-0165

Detections

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