Read the docs
TI-2026-25239 Aliases CVE-2026-32748

Squid has Denial of Service in ICP Response handling

Priority MEDIUM 55CWE-413Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 16 fixed, 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

Squid is a caching proxy for the Web. Prior to version 7.5, due to premature release of resource during expected lifetime and heap Use-After-Free bugs, 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. This bug is fixed in Squid version 7.5.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.09065 95th percentileScored 2026-11-07
Fix Partial squid (squid-cache): 7.5Red Hat: 12 advisoriesRed Hat: 16 fixed, 1 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

VendorProductAffected versionsFixed inStatusSource
squid-cachesquidbefore 7.57.5Patch availableCNA
  • squid Vendorsquid-cache Affected before 7.5 Fixed in 7.5 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*before 7.5Vulnerablesquid-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

Red Hat 12 advisories

  • RHSA-2026:20564 Released 2026-05-26 · Red Hat rating Important
    squid:4 security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
  • RHSA-2026:20580 Released 2026-05-26 · Red Hat rating Important
    squid:4 security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +5
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
  • RHSA-2026:20565 Released 2026-05-26 · Red Hat rating Important
    squid:4 security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.aarch64::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.s390x::squid:4 +11
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
Show 9 more Red Hat advisories
  • RHSA-2026:11901 Released 2026-04-29 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) squid-7:6.10-5.el10_0.2
  • RHSA-2026:10255 Released 2026-04-24 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) squid-7:5.5-13.el9_4.5
  • RHSA-2026:10256 Released 2026-04-23 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) squid-7:5.2-1.el9_0.10
  • RHSA-2026:10257 Released 2026-04-23 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) squid-7:5.5-5.el9_2.11
  • RHSA-2026:9220 Released 2026-04-21 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) squid-7:5.5-19.el9_6.3
  • RHSA-2026:8880 Released 2026-04-20 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) squid-7:3.5.20-17.el7_9.16
  • RHSA-2026:8317 Released 2026-04-15 · Red Hat rating Important
    squid:4 security update
    • Red Hat Enterprise Linux AppStream (v. 8) libecap-1.0.1-2.module+el8.9.0+19703+a1da7223.aarch64::squid:4, libecap-1.0.1-2.module+el8.9.0+19703+a1da7223.ppc64le::squid:4, libecap-1.0.1-2.module+el8.9.0+19703+a1da7223.s390x::squid:4 +11
  • RHSA-2026:8119 Released 2026-04-14 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream (v. 10) squid-7:6.10-6.el10_1.3
  • RHSA-2026:6301 Released 2026-03-31 · Red Hat rating Important
    squid security update
    • Red Hat Enterprise Linux AppStream (v. 9) squid-7:5.5-22.el9_7.4

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:8119
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:8317
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:6301
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:20564
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:20565
Red Hat Enterprise Linux AppStream E4S (v.8.6)Fixed RHSA-2026:20565
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:20580
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2026:10256
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:10257
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:11901
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2026:10255
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:9220
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:20564
Red Hat Enterprise Linux AppStream TUS (v.8.6)Fixed RHSA-2026:20565
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:20580
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:8880
Not affected: 2 products
  • Red Hat Enterprise Linux Server (v. 7 ELS)
  • Red Hat Enterprise Linux Server Optional (v. 7 ELS)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-32748

References

Patch 3

  • 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