CVE-2026-66274

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-05. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A pre-authentication attacker could leverage type nesting to cause a StackOverflowError potentially leading to denial of service.

This issue affects Apache Qpid Proton-J: through 0.34.1.

Users are recommended to upgrade to version 0.35.0, which fixes the issue.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
38(Track)
EG Risk 38/100SSVC: 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 computed
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
40%
KEV
Not listed

Published

August 5, 2026

Last Modified

August 7, 2026

Advisory Details (2)

Auto-updated Aug 6, 2026
No patch confirmed yet.
generic

oss-security - CVE-2026-66274: Apache Qpid Proton-J: Unbounded type nesting can lead to pre-authentication stackoverflow

http://www.openwall.com/lists/oss-security/2026/08/04/10
generic
https://lists.apache.org/thread/h7xolzws2by2qhdjf7scbx87foxojb5h

Vendor Advisories for CVE-2026-66274(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 27× in last 7d / 63× 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.

  1. 2026-08-20 23:06 UTCEG score recompute
  2. 2026-08-20 23:05 UTCGHSA enrichment
  3. 2026-08-20 22:56 UTCEPSS rescore
  4. 2026-08-20 10:01 UTCGHSA enrichment
  5. 2026-08-19 20:57 UTCEG score recompute
  6. 2026-08-19 20:57 UTCGHSA enrichment
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-19 07:50 UTCGHSA enrichment
  9. 2026-08-18 18:42 UTCEG score recompute
  10. 2026-08-18 18:42 UTCGHSA enrichment
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-18 05:37 UTCGHSA enrichment
  13. 2026-08-17 16:32 UTCEG score recompute
  14. 2026-08-17 16:32 UTCGHSA enrichment
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-17 03:08 UTCEG score recompute
  17. 2026-08-17 03:08 UTCGHSA enrichment
  18. 2026-08-16 14:56 UTCEPSS rescore
  19. 2026-08-16 14:03 UTCEG score recompute
  20. 2026-08-16 14:03 UTCGHSA enrichment
  21. 2026-08-16 00:59 UTCGHSA enrichment
  22. 2026-08-15 11:54 UTCEG score recompute
  23. 2026-08-15 11:54 UTCGHSA enrichment
  24. 2026-08-15 01:30 UTCEPSS rescore
  25. 2026-08-14 22:49 UTCGHSA enrichment
Show 38 more
  1. 2026-08-14 09:45 UTCEG score recompute
  2. 2026-08-14 09:45 UTCGHSA enrichment
  3. 2026-08-13 22:00 UTCEPSS rescore
  4. 2026-08-13 20:40 UTCGHSA enrichment
  5. 2026-08-13 07:36 UTCGHSA enrichment
  6. 2026-08-12 18:31 UTCEG score recompute
  7. 2026-08-12 18:31 UTCGHSA enrichment
  8. 2026-08-12 13:51 UTCEPSS rescore
  9. 2026-08-12 05:27 UTCGHSA enrichment
  10. 2026-08-11 16:23 UTCEG score recompute
  11. 2026-08-11 16:23 UTCGHSA enrichment
  12. 2026-08-11 03:18 UTCEG score recompute
  13. 2026-08-11 03:18 UTCGHSA enrichment
  14. 2026-08-11 00:00 UTCEPSS rescore
  15. 2026-08-10 14:14 UTCGHSA enrichment
  16. 2026-08-10 01:09 UTCEG score recompute
  17. 2026-08-10 01:09 UTCGHSA enrichment
  18. 2026-08-09 13:47 UTCEPSS rescore
  19. 2026-08-09 12:05 UTCGHSA enrichment
  20. 2026-08-08 23:00 UTCEG score recompute
  21. 2026-08-08 23:00 UTCGHSA enrichment
  22. 2026-08-08 16:37 UTCEPSS rescore
  23. 2026-08-08 09:55 UTCGHSA enrichment
  24. 2026-08-07 20:51 UTCEG score recompute
  25. 2026-08-07 20:51 UTCGHSA enrichment
  26. 2026-08-07 11:42 UTCEG score recompute
  27. 2026-08-07 11:42 UTCGHSA enrichment
  28. 2026-08-06 22:36 UTCEG score recompute▲ 7.50
  29. 2026-08-06 22:36 UTCGHSA enrichment
  30. 2026-08-06 22:36 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
  31. 2026-08-06 16:06 UTCEG score recompute
  32. 2026-08-06 16:06 UTCGHSA enrichment
  33. 2026-08-06 13:47 UTCEPSS rescore
  34. 2026-08-05 19:17 UTCEPSS rescore
  35. 2026-08-05 19:17 UTCEPSS rescore
  36. 2026-08-05 07:19 UTCNVD update
  37. 2026-08-05 06:21 UTCEG score recompute
  38. 2026-08-05 06:20 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-66274?
CVE-2026-66274 is a high vulnerability published on August 5, 2026. A pre-authentication attacker could leverage type nesting to cause a StackOverflowError potentially leading to denial of service. This issue affects Apache Qpid Proton-J: through 0.34.1. Users are recommended to upgrade to version 0.35.0, which fixes the issue.
When was CVE-2026-66274 disclosed?
CVE-2026-66274 was first published in the National Vulnerability Database on August 5, 2026, with the most recent update on August 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66274 actively exploited?
CVE-2026-66274 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 59.6% of all scored CVEs.
What is the CVSS score of CVE-2026-66274?
CVE-2026-66274 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-66274?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66274, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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