CVE-2026-33526

Squid vulnerable to Denial of Service in ICP Request handling

HIGH
7.5
CVSS Score
Published: March 26, 2026 at 12:16 AM UTC
Updated: July 15, 2026 at 02:20 AM UTC
2 products affected across 1 vendorSquidCache Squid

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Severity
HIGH7.5
Exploit prediction
EPSS 9%
SSVC
No known exploit

Description

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 against the Squid service using ICP protocol. This attack is limited to Squid deployments that explicitly enable ICP support (i.e. configure non-zero `icp_port`). This problem _cannot_ be mitigated by denying ICP queries using `icp_access` rules. Version 7.5 contains a patch.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 7.5
Affected range stops below 7.5, so it looks safe — our inference, not a vendor statement
v < 7.5
Affected range stops below 7.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (18)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/squid-cache/squid/security/advisories/GHSA-hpfx-h48q-gvwg
Third Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2026/03/25/2
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:10255
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:10256
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:10257
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:11901
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:20564

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHredhat-SADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-416CWE-826CWE-825

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