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Fencer Vulns
high 7.5

CVE-2026-32748 json

Squid has Denial of Service in ICP Response handling

published 2026-03-26 7 mo ago modified 2026-07-15 3 mo ago also EUVD-2026-16056

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
9.1%
EPSS 9.1% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

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.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 7:6.10-6.el10_1.3
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 7:6.10-5.el10_0.2
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support 7:3.5.20-17.el7_9.16
  • Red Hat Red Hat Enterprise Linux 8 8100020260408092701.489197e6
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 8040020260514123440.522a0ee4
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 8040020260514123440.522a0ee4
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 8060020260518090356.ad008a3a
  • Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service 8060020260518090356.ad008a3a
  • Red Hat Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions 8060020260518090356.ad008a3a
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 8080020260514105733.63b34585
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 8080020260514105733.63b34585
  • Red Hat Red Hat Enterprise Linux 9 7:5.5-22.el9_7.4
  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions 7:5.2-1.el9_0.10
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 7:5.5-5.el9_2.11
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support 7:5.5-13.el9_4.5
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 7:5.5-19.el9_6.3
  • squid Debian 13 6.13-2+deb13u3
  • squid Debian 14 7.5-1

debian advisories DEBIAN-CVE-2026-32748

  • squid Ubuntu 22.04 LTS 5.9-0ubuntu0.22.04.5
  • squid Ubuntu 24.04 LTS 6.14-0ubuntu0.24.04.2
  • squid Ubuntu 25.10 6.14-0ubuntu0.25.10.2
  • squid Ubuntu Pro 20.04 LTS 4.10-1ubuntu1.13+esm3
  • squid3 Ubuntu Pro 16.04 LTS 3.5.12-1ubuntu7.16+esm7
  • squid3 Ubuntu Pro 18.04 LTS 3.5.27-1ubuntu1.14+esm6

ubuntu advisories UBUNTU-CVE-2026-32748

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • squid RHEL 8 7:4.15-10.module+el8.10.0+24189+04a20c8a.11
  • libecap RHEL 8 1.0.1-2.module+el8.9.0+19703+a1da7223
  • squid RHEL 10.1 7:6.10-6.el10_1.3
  • squid RHEL 9 7:5.5-22.el9_7.4
  • squid RHEL 8.8 TUS, RHEL 8.8 E4S 7:4.15-6.module+el8.8.0+24284+6402ee68.10
  • libecap RHEL 8.8 TUS, RHEL 8.8 E4S, RHEL 8.6 TUS +4 more 1.0.1-2.module+el8.1.0+4044+36416a77
  • squid RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 7:4.11-4.module+el8.4.0+24287+ae9ea41b.11
  • squid RHEL 8.6 TUS, RHEL 8.6 E4S, RHEL 8.6 AUS 7:4.15-3.module+el8.6.0+24307+cba8e5bb.9

red hat advisories RHSA-2026:20580RHSA-2026:20564RHSA-2026:20565RHSA-2026:11901RHSA-2026:10257RHSA-2026:10255

  • squid SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 5.7-150400.3.41.1
  • squid SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Server Applications 15 SP7 6.14-150600.3.20.1
  • squid SLES for SAP applications 16.0, SLES 16.0 6.14-160000.1.1

suse advisories SUSE-SU-2026:4909-1SUSE-SU-2026:4621-1SUSE-SU-2026:24224-1

  • squid openSUSE Leap 16.0 6.14-160000.1.1

opensuse advisories openSUSE-SU-2026:22080-1

  • squid AlmaLinux 8 7:4.15-10.module_el8.10.0+4163+e77fcdac.11
  • libecap AlmaLinux 8 1.0.1-2.module_el8.6.0+2741+01592ae8
  • libecap AlmaLinux 8 1.0.1-2.module_el8.6.0+3048+383bc947
  • squid AlmaLinux 10 7:6.10-6.el10_1.3
  • squid AlmaLinux 9 7:5.5-22.el9_7.4

almalinux advisories ALSA-2026:8317ALSA-2026:8119ALSA-2026:6301

  • squid Rocky Linux 8 7:4.15-10.module+el8.10.0+1928+e8441768.5
  • squid Rocky Linux 8 7:4.15-10.module+el8.10.0+1985+eaf982f0.6
  • squid Rocky Linux 8 7:4.15-10.module+el8.10.0+1885+e30b7122.3
  • squid Rocky Linux 8 7:4.15-10.module+el8.10.0+2080+49064dbd.9
  • squid Rocky Linux 8 7:4.15-10.module+el8.10.0+1758+80ba9f4b
  • squid Rocky Linux 8 7:4.15-10.module+el8.10.0+1881+7e31fb44.1
  • libecap Rocky Linux 8 1.0.1-2.module+el8.9.0+1437+df5ea8f0
  • squid Rocky Linux 10 7:6.10-6.el10_1.3

rocky linux advisories RLSA-2026:8317RLSA-2026:8119RLSA-2026:6301

  • squid Azure Linux 3.0 6.13-4

azure linux advisories AZL-80768

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-32748 updated cvss 7.5

Squid: Squid: Denial of Service via crafted ICP traffic

  • Red Hat Enterprise Linux 6 squid, squid34
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) libecap 1.0.1-2.module+el8.9.0+19703+a1da7223, squid 4.15-10.module+el8.10.0+24189+04a20c8a.11
    fixed: vendor fix RHSA-2026:8317
  • Red Hat Enterprise Linux AppStream (v. 9) squid 5.5-22.el9_7.4
    fixed: vendor fix RHSA-2026:6301
  • Red Hat Enterprise Linux AppStream (v. 10) squid 6.10-6.el10_1.3
    fixed: vendor fix RHSA-2026:8119
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.11-4.module+el8.4.0+24287+ae9ea41b.11
    fixed: vendor fix RHSA-2026:20564
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.15-3.module+el8.6.0+24307+cba8e5bb.9 Red Hat Enterprise Linux AppStream E4S (v.8.6) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.15-3.module+el8.6.0+24307+cba8e5bb.9
    fixed: vendor fix RHSA-2026:20565
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.15-6.module+el8.8.0+24284+6402ee68.10
    fixed: vendor fix RHSA-2026:20580
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) squid 5.2-1.el9_0.10
    fixed: vendor fix RHSA-2026:10256
show 9 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) squid 5.5-5.el9_2.11
    fixed: vendor fix RHSA-2026:10257
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) squid 6.10-5.el10_0.2
    fixed: vendor fix RHSA-2026:11901
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) squid 5.5-13.el9_4.5
    fixed: vendor fix RHSA-2026:10255
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) squid 5.5-19.el9_6.3
    fixed: vendor fix RHSA-2026:9220
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.11-4.module+el8.4.0+24287+ae9ea41b.11
    fixed: vendor fix RHSA-2026:20564
  • Red Hat Enterprise Linux AppStream TUS (v.8.6) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.15-3.module+el8.6.0+24307+cba8e5bb.9
    fixed: vendor fix RHSA-2026:20565
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) libecap 1.0.1-2.module+el8.1.0+4044+36416a77, squid 4.15-6.module+el8.8.0+24284+6402ee68.10
    fixed: vendor fix RHSA-2026:20580
  • Red Hat Enterprise Linux Server (v. 7 ELS) squid 3.5.20-17.el7_9.16
    fixed: vendor fix RHSA-2026:8880
  • Red Hat Enterprise Linux Server (v. 7 ELS) squid-migration-script 3.5.20-17.el7_9.16 Red Hat Enterprise Linux Server Optional (v. 7 ELS) squid-sysvinit 3.5.20-17.el7_9.16
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

9.06% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • squid-cache squid
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 6

Classification

Weakness
  • CWE-413 Improper Resource Locking
  • CWE-416 Use After Free
  • CWE-826 Premature Release of Resource During Expected Lifetime

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.