CVE-2026-67591

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory published 2026-08-05. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

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

An authenticated attacker could exceed the session flow control incoming window potentially leading to denial of service.

This issue affects Apache Qpid ProtonJ2: through 1.1.0.

Users are recommended to upgrade to version 1.2.0, which fixes the issue.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 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 (2)

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

oss-security - CVE-2026-67591: Apache Qpid ProtonJ2: Incoming session flow control window can be exceeded

http://www.openwall.com/lists/oss-security/2026/08/04/30

Vendor Advisories for CVE-2026-67591(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 17× in last 7d / 73× 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 132 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-67591?
CVE-2026-67591 is a medium vulnerability published on August 5, 2026. An authenticated attacker could exceed the session flow control incoming window potentially leading to denial of service. This issue affects Apache Qpid ProtonJ2: through 1.1.0. Users are recommended to upgrade to version 1.2.0, which fixes the issue.
When was CVE-2026-67591 disclosed?
CVE-2026-67591 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-2026-67591 actively exploited?
CVE-2026-67591 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 63.9% of all scored CVEs.
What is the CVSS score of CVE-2026-67591?
CVE-2026-67591 has a CVSS v3.1 base score of 6.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-67591?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-67591, 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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