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.
CVE-2026-33526
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 8.9%, top 5% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 52(Track)EG Risk 52/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation9% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 9%
- EPSS %ILE
- 95%
- KEV
- Not listed
Published
March 26, 2026
Last Modified
July 15, 2026
Advisory Details (10)
Auto-updated Jul 3, 2026Affected: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions and Red Hat Enterprise Linux 8.8 Telecommunications Update Serv
https://access.redhat.com/errata/RHSA-2026:20580Affected: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.6 Update Services for SAP So
https://access.redhat.com/errata/RHSA-2026:20565Affected: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support
https://access.redhat.com/errata/RHSA-2026:20564Affected: Red Hat Enterprise Linux 10.0 Extended Update Support.
https://access.redhat.com/errata/RHSA-2026:11901Affected: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions.
https://access.redhat.com/errata/RHSA-2026:10257Affected: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions.
https://access.redhat.com/errata/RHSA-2026:10256Affected: Red Hat Enterprise Linux 9.4 Extended Update Support.
https://access.redhat.com/errata/RHSA-2026:10255oss-security - [ADVISORY] SQUID-2026:1 Denial of Service in ICP Request handling (CVE-2026-33526)
http://www.openwall.com/lists/oss-security/2026/03/25/2SQUID-2026:1 Denial of Service in ICP Request handling · Advisory · squid-cache/squid · GitHub
https://github.com/squid-cache/squid/security/advisories/GHSA-hpfx-h48q-gvwgcommit 8a7d42f9d44b (squid-cache/squid)
Fix landed in squid-cache/squid commit 8a7d42f9d44b — awaiting tagged release
https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91Vendor Advisories for CVE-2026-33526(11)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- CVE-2026-33526Microsoft Security Response Center (MSRC)High
Squid vulnerable to Denial of Service in ICP Request handling
- RHSA-2026:20565Red Hat Product SecurityHigh
Red Hat Security Advisory: squid:4 security update
- RHSA-2026:11901Red Hat Product SecurityHigh
Red Hat Security Advisory: squid security update
- RHSA-2026:10255Red Hat Product SecurityHigh
Red Hat Security Advisory: squid security update
- RHSA-2026:10256Red Hat Product SecurityHigh
Red Hat Security Advisory: squid security update
- RHSA-2026:10257Red Hat Product SecurityHigh
Red Hat Security Advisory: squid security update
- RHSA-2026:9220Red Hat Product SecurityHigh
Red Hat Security Advisory: squid security update
- RHSA-2026:8880Red Hat Product SecurityHigh
Red Hat Security Advisory: squid security update
- +3 more
Patch Availability(12)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| redhat | squid:4-8060020260518090356.ad008a3a | 2026-05-26 | redhat |
| redhat | squid:4-8040020260514123440.522a0ee4 | 2026-05-26 | redhat |
| redhat | squid:4-8080020260514105733.63b34585 | 2026-05-26 | redhat |
| redhat | squid-7:6.10-5.el10_0.2 | 2026-04-29 | redhat |
| redhat | squid-7:5.5-13.el9_4.5 | 2026-04-24 | redhat |
| redhat | squid-7:5.2-1.el9_0.10 | 2026-04-23 | redhat |
| redhat | squid-7:5.5-5.el9_2.11 | 2026-04-23 | redhat |
| redhat | squid-7:5.5-19.el9_6.3 | 2026-04-21 | redhat |
| redhat | squid-7:3.5.20-17.el7_9.16 | 2026-04-20 | redhat |
| redhat | squid:4-8100020260408092701.489197e6 | 2026-04-15 | redhat |
| redhat | squid-7:6.10-6.el10_1.3 | 2026-04-14 | redhat |
| redhat | squid-7:5.5-22.el9_7.4 | 2026-03-31 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(4 across 4 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| squid | 4.13-10 ... 4.13-10+deb11u6 (7 versions) | 4.13-10+deb11u7 | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| squid | 5.7-2 ... 5.7-2+deb12u5 (6 versions) | 5.7-2+deb12u6 | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| squid | 6.13-2, 6.13-2+deb13u1 | 6.13-2+deb13u2 | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| squid | 6.13-2, 7.1-1, 7.2-1, 7.2-2, 7.4-1 | 7.5-1 | — |
Weakness Classification(3)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(3)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
Data Freshness Timeline
(refreshed 7× in last 7d / 52× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-24 14:17 UTCEPSS rescore
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-19 17:03 UTCEPSS rescore
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 10:12 UTCEG score recompute
- 2026-08-16 10:12 UTCVendor advisory
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-14 19:28 UTCVendor advisory
- 2026-08-14 06:29 UTCEG score recompute
- 2026-08-14 06:29 UTCVendor advisory
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-12 20:46 UTCEG score recompute
- 2026-08-12 20:46 UTCVendor advisory
- 2026-08-12 13:50 UTCEPSS rescore
- 2026-08-11 20:52 UTCEG score recompute
- 2026-08-11 20:52 UTCVendor advisory
- 2026-08-11 03:54 UTCVendor advisory
- 2026-08-10 05:39 UTCVendor advisory
Show 62 moreShow fewer
- 2026-08-09 17:50 UTCEG score recompute
- 2026-08-09 17:50 UTCVendor advisory
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-09 06:02 UTCEG score recompute
- 2026-08-09 06:02 UTCVendor advisory
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-08 04:14 UTCEG score recompute
- 2026-08-08 04:14 UTCVendor advisory
- 2026-08-07 16:26 UTCVendor advisory
- 2026-08-06 18:49 UTCEG score recompute
- 2026-08-06 18:49 UTCVendor advisory
- 2026-08-06 13:46 UTCEPSS rescore
- 2026-08-06 00:55 UTCEG score recompute
- 2026-08-06 00:55 UTCVendor advisory
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 10:38 UTCEPSS rescore
- 2026-08-03 23:38 UTCEG score recompute
- 2026-08-03 23:38 UTCVendor advisory
- 2026-08-03 10:36 UTCEPSS rescore
- 2026-08-02 15:26 UTCEG score recompute
- 2026-08-02 15:26 UTCVendor advisory
- 2026-08-02 02:27 UTCEPSS rescore
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-30 16:28 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-27 14:13 UTCEPSS rescore
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-24 14:17 UTCEPSS rescore
- 2026-07-24 14:17 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:09 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-18 06:59 UTCOSV refresh
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-13 22:30 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-08 15:15 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 04:32 UTCEG score recompute
- 2026-06-30 04:32 UTCVendor advisory
- 2026-06-30 04:32 UTCNVD updatefirst tracked
Related CVEs(same vendor + same CWE)
Same vendor
10 shownredhat
- CVE-2001-0825EG 10.0HIGH
- CVE-2001-0554EG 10.0EPSS p98HIGH
- CVE-2001-0414EG 10.0EPSS p100HIGH
- CVE-2001-0191EG 10.0EPSS p92HIGH
- CVE-2001-0301EG 10.0EPSS p91HIGH
- CVE-2001-0197EG 10.0EPSS p96HIGH
- CVE-2001-0233EG 10.0EPSS p96HIGH
- CVE-2001-0010EG 10.0EPSS p98HIGH
- CVE-2001-0011EG 10.0EPSS p94HIGH
- CVE-2001-0013EG 10.0EPSS p95HIGH
Frequently asked(5)
What is CVE-2026-33526?
When was CVE-2026-33526 disclosed?
Is CVE-2026-33526 actively exploited?
What is the CVSS score of CVE-2026-33526?
How do I remediate CVE-2026-33526?
Dependency Blast Radius
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