CVE-2026-33526

HIGHNVD 7.57.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 9.1% (95th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 3 sources updated this weekElevated

Also known asEUVD-2026-16068 (ENISA EUVD)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 9.1%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
9.1%
EPSS %ILE
95th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
9.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-30). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

March 26, 2026

Last Modified

July 15, 2026

Advisory Details (10)

Auto-updated Jul 3, 2026
Patch available. Sources: github_commit, github, redhat.
Red HatMentions a patch (unverified)

Affected: 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-2026:20580
Red HatMentions a patch (unverified)

Affected: 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-2026:20565
Red HatMentions a patch (unverified)

Affected: 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-2026:20564
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 10.0 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:11901
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions.

https://access.redhat.com/errata/RHSA-2026:10257
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions.

https://access.redhat.com/errata/RHSA-2026:10256
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.4 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:10255
Web pageMentions a patch (unverified)

oss-security - [ADVISORY] SQUID-2026:1 Denial of Service in ICP Request handling (CVE-2026-33526)

http://www.openwall.com/lists/oss-security/2026/03/25/2
GitHub advisoryMentions a patch (unverified)

SQUID-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-gvwg
GitHub commit

commit 8a7d42f9d44b (squid-cache/squid)

Fix landed in squid-cache/squid commit 8a7d42f9d44b — awaiting tagged release

https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91

Patch Availability(14)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntusquidclient (3.5.12-1ubuntu7.16+esm7) @ xenial2026-10-24ubuntu
ubuntusquidclient (5.9-0ubuntu0.22.04.5) @ jammy2026-10-24ubuntu
redhatsquid:4-8040020260514123440.522a0ee42026-05-26redhat
redhatsquid:4-8080020260514105733.63b345852026-05-26redhat
redhatsquid:4-8060020260518090356.ad008a3a2026-05-26redhat
redhatsquid-7:6.10-5.el10_0.22026-04-29redhat
redhatsquid-7:5.5-13.el9_4.52026-04-24redhat
redhatsquid-7:5.2-1.el9_0.102026-04-23redhat
redhatsquid-7:5.5-5.el9_2.112026-04-23redhat
redhatsquid-7:5.5-19.el9_6.32026-04-21redhat
redhatsquid-7:3.5.20-17.el7_9.162026-04-20redhat
redhatsquid:4-8100020260408092701.489197e62026-04-15redhat
redhatsquid-7:6.10-6.el10_1.32026-04-14redhat
redhatsquid-7:5.5-22.el9_7.42026-03-31redhat

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)
PackageVulnerable rangeFix by version rangeDependents
squid4.13-10 ... 4.13-10+deb11u6 (7 versions)
  • every version up to 4.13-10+deb11u7: fixed in 4.13-10+deb11u7
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
squid5.7-2 ... 5.7-2+deb12u5 (6 versions)
  • every version up to 5.7-2+deb12u6: fixed in 5.7-2+deb12u6
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
squid6.13-2, 6.13-2+deb13u1
  • every version up to 6.13-2+deb13u2: fixed in 6.13-2+deb13u2
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
squid6.13-2, 7.1-1, 7.2-1, 7.2-2, 7.4-1
  • every version up to 7.5-1: fixed in 7.5-1
—

Weakness Classification(3)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(2)

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 8× in last 7d / 40× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 96 of 156 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 4 repeat rows among the latest 100 are merged into the row they repeat. The 60 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-31 16:32 UTCEPSS rescoreEPSS 9.1% · 95th percentile
  2. 2026-10-31 13:52 UTCEG score recompute
  3. 2026-10-31 13:52 UTCVendor advisory
  4. 2026-10-30 16:34 UTCEPSS rescoreEPSS 9.1% · 95th percentile
  5. 2026-10-29 16:33 UTCEPSS rescoreEPSS 9.1% · 95th percentile
  6. 2026-10-28 16:32 UTCEPSS rescoreEPSS 9.1% · 95th percentile
  7. 2026-10-27 16:31 UTCEPSS rescoreEPSS 9.1% · 95th percentile
  8. 2026-10-26 16:31 UTCEPSS rescoreEPSS 9.1% · 95th percentile
  9. 2026-10-25 16:32 UTCEPSS rescoreEPSS 9.1% · 95th percentile
  10. 2026-10-25 14:34 UTCEG score recompute
  11. 2026-10-24 16:32 UTCEPSS rescoreEPSS 9.1% · 95th percentile
  12. 2026-10-24 14:47 UTCEG score recompute
  13. 2026-10-24 14:47 UTCVendor advisory
  14. 2026-10-23 16:31 UTCEPSS rescoreEPSS 9.1% · 95th percentile
  15. 2026-10-22 16:34 UTCEPSS rescoreEPSS 8.9% · 95th percentile
  16. 2026-10-21 16:32 UTCEPSS rescoreEPSS 8.9% · 95th percentile
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 8.9% · 95th percentile
  18. 2026-10-19 16:31 UTCEPSS rescoreEPSS 8.9% · 95th percentile
  19. 2026-10-18 03:46 UTCEG score recompute
  20. 2026-10-17 16:34 UTCEPSS rescoreEPSS 8.9% · 95th percentile
  21. 2026-10-17 15:44 UTCEG score recompute
  22. 2026-10-17 15:44 UTCVendor advisory
  23. 2026-10-16 16:41 UTCEPSS rescoreEPSS 8.9% · 95th percentile
  24. 2026-10-15 16:32 UTCEPSS rescoreEPSS 8.9% · 95th percentile
  25. 2026-10-14 16:32 UTCEPSS rescoreEPSS 8.9% · 95th percentile
Show 71 more
  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 13% · 96th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 13% · 96th percentile
  3. 2026-10-12 16:13 UTCEG score recompute
  4. 2026-10-11 19:55 UTCEG score recompute
  5. 2026-10-11 17:09 UTCEG score recompute
  6. 2026-10-11 14:36 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 13% · 96th percentile
  8. 2026-10-11 05:55 UTCOSV refresh
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 13% · 96th percentile
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 13% · 96th percentile
  11. 2026-10-08 17:12 UTCEPSS rescoreEPSS 13% · 96th percentile
  12. 2026-10-07 23:47 UTCEPSS rescoreEPSS 13% · 96th percentile
  13. 2026-10-06 15:17 UTCEPSS rescoreEPSS 13% · 96th percentile
  14. 2026-10-05 17:42 UTCEPSS rescoreEPSS 13% · 96th percentile
  15. 2026-10-03 14:25 UTCEPSS rescoreEPSS 13% · 96th percentile
  16. 2026-10-01 19:49 UTCEPSS rescoreEPSS 13% · 96th percentile
  17. 2026-09-30 15:03 UTCEPSS rescoreEPSS 13% · 96th percentile
  18. 2026-09-28 13:51 UTCEPSS rescoreEPSS 13% · 96th percentile
  19. 2026-09-27 13:48 UTCEPSS rescoreEPSS 13% · 96th percentile
  20. 2026-09-26 15:58 UTCEPSS rescoreEPSS 13% · 96th percentile
  21. 2026-09-26 00:26 UTCEPSS rescoreEPSS 13% · 96th percentile
  22. 2026-09-21 17:49 UTCOSV refresh
  23. 2026-09-18 19:28 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  24. 2026-09-17 19:30 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  25. 2026-09-16 14:08 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  26. 2026-09-16 05:15 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  27. 2026-09-15 03:11 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  28. 2026-09-13 16:47 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  29. 2026-09-12 15:01 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  30. 2026-09-11 14:53 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  31. 2026-09-11 09:37 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  32. 2026-09-10 09:34 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  33. 2026-09-08 22:00 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  34. 2026-09-07 16:01 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  35. 2026-09-06 13:47 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  36. 2026-09-04 05:06 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  37. 2026-09-02 14:11 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  38. 2026-09-02 14:01 UTCOSV refresh
  39. 2026-09-01 13:53 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  40. 2026-09-01 04:39 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  41. 2026-08-30 19:17 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  42. 2026-08-30 01:22 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  43. 2026-08-28 21:41 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  44. 2026-08-27 14:25 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  45. 2026-08-26 14:46 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  46. 2026-08-25 13:49 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  47. 2026-08-24 14:17 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  48. 2026-08-23 00:19 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  49. 2026-08-21 23:49 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  50. 2026-08-20 22:55 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  51. 2026-08-19 17:03 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  52. 2026-08-18 13:48 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  53. 2026-08-17 13:47 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  54. 2026-08-16 14:56 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  55. 2026-08-16 10:12 UTCEG score recompute
  56. 2026-08-16 10:12 UTCVendor advisory
  57. 2026-08-16 02:14 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  58. 2026-08-15 01:30 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  59. 2026-08-14 19:28 UTCVendor advisory
  60. 2026-08-14 06:29 UTCEG score recompute
  61. 2026-08-14 06:29 UTCVendor advisory
  62. 2026-08-13 22:00 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  63. 2026-08-12 20:46 UTCEG score recompute
  64. 2026-08-12 20:46 UTCVendor advisory
  65. 2026-08-12 13:50 UTCEPSS rescoreEPSS 8.9% · 94th percentile
  66. 2026-08-11 20:52 UTCEG score recompute
  67. 2026-08-11 20:52 UTCVendor advisory
  68. 2026-08-11 03:54 UTCVendor advisory
  69. 2026-08-10 05:39 UTCVendor advisory
  70. 2026-08-09 17:50 UTCEG score recompute
  71. 2026-08-09 17:50 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-33526?
CVE-2026-33526 is a high-severity vulnerability; its CVE record was published on March 26, 2026. 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…
When was the CVE record for CVE-2026-33526 published?
The CVE record for CVE-2026-33526 was published on March 26, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 15, 2026; the record at its source may have been updated since.
Is CVE-2026-33526 actively exploited?
CVE-2026-33526 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 9.1% probability of exploitation in the next 30 days (95th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33526?
CVE-2026-33526 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-33526?
A fix for CVE-2026-33526 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-33526 are linked in the Vendor Advisories panel on this page.

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