CVE-2026-66257

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM 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 — 4 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

A fix is available — apply it.

A pre-authentication attacker could leverage unbounded symbol value caching to cause resource exhaustion 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(medium)
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
37%
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/dnczt6bgfcq2x6q8ljco177h1qmv59fm

Vendor Advisories for CVE-2026-66257(4)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatproton-j2026-09-10redhat

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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 35× in last 7d / 125× 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.

Showing the most recent 100 of 192 total refreshes for this CVE.

  1. 2026-09-19 03:31 UTCEG score recompute
  2. 2026-09-19 03:31 UTCVendor advisory
  3. 2026-09-19 03:31 UTCGHSA enrichment
  4. 2026-09-18 19:28 UTCEPSS rescore
  5. 2026-09-18 15:08 UTCVendor advisory
  6. 2026-09-18 15:08 UTCGHSA enrichment
  7. 2026-09-18 03:36 UTCEG score recompute
  8. 2026-09-18 03:36 UTCVendor advisory
  9. 2026-09-18 03:36 UTCGHSA enrichment
  10. 2026-09-17 16:06 UTCVendor advisory
  11. 2026-09-17 16:06 UTCGHSA enrichment
  12. 2026-09-17 01:09 UTCEG score recompute
  13. 2026-09-17 01:09 UTCVendor advisory
  14. 2026-09-17 01:09 UTCGHSA enrichment
  15. 2026-09-16 14:08 UTCEPSS rescore
  16. 2026-09-16 05:15 UTCEPSS rescore
  17. 2026-09-16 05:15 UTCVendor advisory
  18. 2026-09-16 05:15 UTCGHSA enrichment
  19. 2026-09-15 16:42 UTCEG score recompute
  20. 2026-09-15 16:42 UTCVendor advisory
  21. 2026-09-15 16:42 UTCGHSA enrichment
  22. 2026-09-15 02:43 UTCVendor advisory
  23. 2026-09-15 02:43 UTCGHSA enrichment
  24. 2026-09-14 14:43 UTCVendor advisory
  25. 2026-09-14 14:43 UTCGHSA enrichment
Show 75 more
  1. 2026-09-14 03:13 UTCEG score recompute
  2. 2026-09-14 03:13 UTCVendor advisory
  3. 2026-09-14 03:13 UTCGHSA enrichment
  4. 2026-09-13 15:44 UTCVendor advisory
  5. 2026-09-13 15:44 UTCGHSA enrichment
  6. 2026-09-13 04:15 UTCVendor advisory
  7. 2026-09-13 04:15 UTCGHSA enrichment
  8. 2026-09-12 16:45 UTCEG score recompute
  9. 2026-09-12 16:45 UTCVendor advisory
  10. 2026-09-12 16:45 UTCGHSA enrichment
  11. 2026-09-12 05:16 UTCVendor advisory
  12. 2026-09-12 05:16 UTCGHSA enrichment
  13. 2026-09-11 17:46 UTCEG score recompute
  14. 2026-09-11 17:46 UTCVendor advisory
  15. 2026-09-11 17:46 UTCGHSA enrichment
  16. 2026-09-11 14:53 UTCEPSS rescore
  17. 2026-09-11 09:37 UTCEPSS rescore
  18. 2026-09-11 06:14 UTCVendor advisory
  19. 2026-09-11 06:14 UTCGHSA enrichment
  20. 2026-09-10 18:44 UTCEG score recompute
  21. 2026-09-10 18:44 UTCVendor advisory
  22. 2026-09-10 18:44 UTCGHSA enrichment
  23. 2026-09-10 06:53 UTCVendor advisory
  24. 2026-09-10 06:53 UTCGHSA enrichment
  25. 2026-09-09 19:24 UTCVendor advisory
  26. 2026-09-09 19:24 UTCGHSA enrichment
  27. 2026-09-09 06:31 UTCEG score recompute
  28. 2026-09-09 06:31 UTCVendor advisory
  29. 2026-09-09 06:31 UTCGHSA enrichment
  30. 2026-09-08 22:01 UTCEPSS rescore
  31. 2026-09-08 08:14 UTCVendor advisory
  32. 2026-09-08 08:14 UTCGHSA enrichment
  33. 2026-09-07 18:26 UTCEG score recompute
  34. 2026-09-07 18:26 UTCVendor advisory
  35. 2026-09-07 18:26 UTCGHSA enrichment
  36. 2026-09-07 16:01 UTCEPSS rescore
  37. 2026-09-06 17:29 UTCEG score recompute
  38. 2026-09-06 17:29 UTCVendor advisory
  39. 2026-09-06 17:29 UTCGHSA enrichment
  40. 2026-09-06 13:47 UTCEPSS rescore
  41. 2026-09-06 05:59 UTCVendor advisory
  42. 2026-09-06 05:59 UTCGHSA enrichment
  43. 2026-09-05 18:30 UTCEG score recompute
  44. 2026-09-05 18:30 UTCVendor advisory
  45. 2026-09-05 18:30 UTCGHSA enrichment
  46. 2026-09-05 15:31 UTCEPSS rescore
  47. 2026-09-05 04:00 UTCEG score recompute
  48. 2026-09-05 04:00 UTCVendor advisory
  49. 2026-09-05 04:00 UTCGHSA enrichment
  50. 2026-09-04 10:01 UTCEG score recompute
  51. 2026-09-04 10:01 UTCVendor advisory
  52. 2026-09-04 10:01 UTCGHSA enrichment
  53. 2026-09-04 05:07 UTCEPSS rescore
  54. 2026-09-03 20:36 UTCGHSA enrichment
  55. 2026-09-03 07:15 UTCEG score recompute
  56. 2026-09-03 07:14 UTCGHSA enrichment
  57. 2026-09-02 14:12 UTCEPSS rescore
  58. 2026-09-02 08:19 UTCGHSA enrichment
  59. 2026-09-01 20:46 UTCEG score recompute
  60. 2026-09-01 20:46 UTCGHSA enrichment
  61. 2026-09-01 13:54 UTCEPSS rescore
  62. 2026-09-01 04:40 UTCEPSS rescore
  63. 2026-08-31 22:56 UTCGHSA enrichment
  64. 2026-08-30 21:27 UTCEG score recompute
  65. 2026-08-30 21:27 UTCGHSA enrichment
  66. 2026-08-30 19:17 UTCEPSS rescore
  67. 2026-08-30 09:58 UTCEG score recompute
  68. 2026-08-30 09:58 UTCGHSA enrichment
  69. 2026-08-30 01:22 UTCEPSS rescore
  70. 2026-08-29 21:37 UTCEG score recompute
  71. 2026-08-29 21:37 UTCGHSA enrichment
  72. 2026-08-28 21:42 UTCEPSS rescore
  73. 2026-08-27 19:56 UTCEG score recompute
  74. 2026-08-27 19:56 UTCGHSA enrichment
  75. 2026-08-27 08:14 UTCGHSA enrichment

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-66257?
CVE-2026-66257 is a high vulnerability published on August 5, 2026. A pre-authentication attacker could leverage unbounded symbol value caching to cause resource exhaustion 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-2026-66257 disclosed?
CVE-2026-66257 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-2026-66257 actively exploited?
CVE-2026-66257 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 63.5% of all scored CVEs.
What is the CVSS score of CVE-2026-66257?
CVE-2026-66257 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-66257?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66257, 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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