TI-2026-25911 Aliases CVE-2026-33515

Squid has issues in ICP message handling

LOW 39CWE-125Published 2026-03-26 · Updated 2026-03-26

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: —
Confidentiality · integrity · availability: Low · Low · None
Fix status: Partial Red Hat: 5 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

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 sensitive information when responding with errors to invalid ICP requests. 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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.01058 64th percentileScored 2026-11-07

Fix Partial squid (squid-cache): 7.5Red Hat: 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
squid-cache	squid	before 7.5	7.5	Patch available	CNA

squid Vendorsquid-cache Affected before 7.5 Fixed in 7.5 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:squid-cache:squid::::::::	before 7.5	Vulnerable	squid-cache

cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* Versions before 7.5 Vulnerable ·squid-cache

Remediation

Fix · CNA squid (squid-cache) Fixed in 7.5

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 6	Affected	No fix planned: Out of support scope
Red Hat Enterprise Linux 7	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-33515
2026-10-14 Priority changed: MEDIUM → LOW

References

Patch 1

https://github.com/squid-cache/squid/commit/8138e909d2058d4401e0ad49b583afaec912b165

Advisory 2

Other 2

TI-2025-38486 Squid vulnerable to information disclosure via authentication credential leakage in error handling CVSS 3.1CRITICAL 10.0
TI-2024-16845 Denial of Service in HTTP Header parser in squid proxy CVSS 3.1HIGH 7.5
TI-2024-16566 SQUID-2024:1 Denial of Service in HTTP Chunked Decoding CVSS 3.1HIGH 8.6
TI-2023-26921 Denial of Service in HTTP Message Processing in Squid CVSS 3.1HIGH 8.6
TI-2023-27496 SQUID-2023:10 Denial of Service in HTTP Request parsing CVSS 3.1HIGH 8.6
TI-2023-25306 Squid: denial of service in http digest authentication CVSS 3.1HIGH 8.6

See all 110 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences