CVE-2026-66275

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: 0.7%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

An authenticated attacker could exceed the session flow control incoming window 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
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
34
EG Risk 34/100CISA SSVC

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%
Exploitation1% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
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
0.7%
EPSS %ILE
49th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or 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 (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 5, 2026

Last Modified

August 7, 2026

Advisory Details (2)

Auto-updated Aug 6, 2026
Fix named in the CVE record.
generic

oss-security - CVE-2026-66275: Apache Qpid Proton-J: Incoming session flow control window can be exceeded

http://www.openwall.com/lists/oss-security/2026/08/04/11
generic
https://lists.apache.org/thread/jds59nxrgcxtlx7xl0kvl5hqt07thxzt

Vendor Advisories for CVE-2026-66275(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 13× in last 7d / 60× 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 145 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-66275?
CVE-2026-66275 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 Proton-J: through 0.34.1. Users are recommended to upgrade to version 0.35.0, which fixes the issue.
When was CVE-2026-66275 disclosed?
CVE-2026-66275 was first published 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-2026-66275 actively exploited?
CVE-2026-66275 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (49th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66275?
CVE-2026-66275 has a CVSS v3.1 base score of 6.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-66275?
A fix for CVE-2026-66275 is available — its CVE record says: "Users are recommended to upgrade to version 0.35.0, which fixes the issue." The vendor advisories EchelonGraph has for CVE-2026-66275 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-66275

Explore →

Is Your Infrastructure Affected by CVE-2026-66275?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs