CVE-2026-66273

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 size/count handling to cause excessive allocation leading to potential 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
49(Track)
EG Risk 49/100SSVC: 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%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

August 5, 2026

Last Modified

August 7, 2026

Advisory Details (1)

Auto-updated Aug 6, 2026
No patch confirmed yet.
generic
https://lists.apache.org/thread/z34s9v5w05qk4qqtz5fs3v9wpxz6fnbh

Vendor Advisories for CVE-2026-66273(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 26× in last 7d / 68× 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. 2026-08-21 03:19 UTCEG score recompute
  2. 2026-08-21 03:19 UTCGHSA enrichment
  3. 2026-08-20 22:56 UTCEPSS rescore
  4. 2026-08-20 14:20 UTCGHSA enrichment
  5. 2026-08-19 23:43 UTCEG score recompute
  6. 2026-08-19 23:43 UTCGHSA enrichment
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-19 10:43 UTCGHSA enrichment
  9. 2026-08-18 21:43 UTCEG score recompute
  10. 2026-08-18 21:43 UTCGHSA enrichment
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-18 08:39 UTCGHSA enrichment
  13. 2026-08-17 19:38 UTCEG score recompute
  14. 2026-08-17 19:38 UTCGHSA enrichment
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-17 06:39 UTCGHSA enrichment
  17. 2026-08-16 17:40 UTCEG score recompute
  18. 2026-08-16 17:40 UTCGHSA enrichment
  19. 2026-08-16 14:56 UTCEPSS rescore
  20. 2026-08-16 04:34 UTCEG score recompute
  21. 2026-08-16 04:34 UTCGHSA enrichment
  22. 2026-08-15 15:35 UTCGHSA enrichment
  23. 2026-08-15 02:35 UTCEG score recompute
  24. 2026-08-15 02:35 UTCGHSA enrichment
  25. 2026-08-15 01:30 UTCEPSS rescore
Show 43 more
  1. 2026-08-14 13:36 UTCGHSA enrichment
  2. 2026-08-14 00:37 UTCEG score recompute
  3. 2026-08-14 00:37 UTCGHSA enrichment
  4. 2026-08-13 22:00 UTCEPSS rescore
  5. 2026-08-13 11:37 UTCGHSA enrichment
  6. 2026-08-12 22:38 UTCEG score recompute
  7. 2026-08-12 22:38 UTCGHSA enrichment
  8. 2026-08-12 13:51 UTCEPSS rescore
  9. 2026-08-12 09:39 UTCGHSA enrichment
  10. 2026-08-11 20:40 UTCEG score recompute
  11. 2026-08-11 20:40 UTCGHSA enrichment
  12. 2026-08-11 07:41 UTCEG score recompute
  13. 2026-08-11 07:41 UTCGHSA enrichment
  14. 2026-08-11 00:00 UTCEPSS rescore
  15. 2026-08-10 18:42 UTCGHSA enrichment
  16. 2026-08-10 05:42 UTCGHSA enrichment
  17. 2026-08-09 16:43 UTCEG score recompute
  18. 2026-08-09 16:43 UTCGHSA enrichment
  19. 2026-08-09 13:47 UTCEPSS rescore
  20. 2026-08-09 03:44 UTCEG score recompute
  21. 2026-08-09 03:44 UTCGHSA enrichment
  22. 2026-08-08 16:37 UTCEPSS rescore
  23. 2026-08-08 14:45 UTCGHSA enrichment
  24. 2026-08-08 01:45 UTCEG score recompute
  25. 2026-08-08 01:45 UTCGHSA enrichment
  26. 2026-08-07 12:46 UTCGHSA enrichment
  27. 2026-08-07 05:05 UTCGHSA enrichment
  28. 2026-08-06 16:06 UTCEG score recompute
  29. 2026-08-06 16:06 UTCGHSA enrichment
  30. 2026-08-06 14:28 UTCGHSA enrichment
  31. 2026-08-06 13:53 UTCEG score recompute▲ 7.50
  32. 2026-08-06 13:53 UTCGHSA enrichment
  33. 2026-08-06 13:52 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  34. 2026-08-06 13:47 UTCEPSS rescore
  35. 2026-08-05 19:17 UTCEPSS rescore
  36. 2026-08-05 19:17 UTCEPSS rescore
  37. 2026-08-05 08:23 UTCGHSA enrichment
  38. 2026-08-05 08:20 UTCNVD update
  39. 2026-08-05 07:24 UTCGHSA enrichment
  40. 2026-08-05 07:20 UTCMITRE cvelistV5
  41. 2026-08-05 06:18 UTCNVD update
  42. 2026-08-05 05:34 UTCEG score recompute
  43. 2026-08-05 05:30 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-66273?
CVE-2026-66273 is a high vulnerability published on August 5, 2026. A pre-authentication attacker could leverage type size/count handling to cause excessive allocation leading to potential 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-2026-66273 disclosed?
CVE-2026-66273 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-2026-66273 actively exploited?
CVE-2026-66273 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 64.2% of all scored CVEs.
What is the CVSS score of CVE-2026-66273?
CVE-2026-66273 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-66273?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66273, 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.

Dependency Blast Radius

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