CVE-2026-67553

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH 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 Proton-Dotnet: through 1.0.0.

Users are recommended to upgrade to version 1.1.0, which fixes the issue.

CVSS v3
6.5
EG Score
6.5(high)
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
35%
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-2026-67553: Apache Qpid Proton Dotnet: Incoming session flow control window can be exceeded

http://www.openwall.com/lists/oss-security/2026/08/04/24
generic
https://lists.apache.org/thread/hvsncmcbgjrn85crs909nf4y3dqqrywo

Vendor Advisories for CVE-2026-67553(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 20× in last 7d / 54× 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 22:56 UTCEPSS rescore
  2. 2026-08-20 17:28 UTCGHSA enrichment
  3. 2026-08-19 18:54 UTCEG score recompute
  4. 2026-08-19 18:54 UTCGHSA enrichment
  5. 2026-08-19 17:04 UTCEPSS rescore
  6. 2026-08-18 19:47 UTCEG score recompute
  7. 2026-08-18 19:47 UTCGHSA enrichment
  8. 2026-08-18 13:48 UTCEPSS rescore
  9. 2026-08-17 21:14 UTCEG score recompute
  10. 2026-08-17 21:14 UTCGHSA enrichment
  11. 2026-08-17 13:47 UTCEPSS rescore
  12. 2026-08-16 22:41 UTCEG score recompute
  13. 2026-08-16 22:41 UTCGHSA enrichment
  14. 2026-08-16 14:56 UTCEPSS rescore
  15. 2026-08-16 00:08 UTCGHSA enrichment
  16. 2026-08-15 01:34 UTCEG score recompute
  17. 2026-08-15 01:34 UTCGHSA enrichment
  18. 2026-08-15 01:30 UTCEPSS rescore
  19. 2026-08-14 03:01 UTCEG score recompute
  20. 2026-08-14 03:01 UTCGHSA enrichment
  21. 2026-08-13 22:00 UTCEPSS rescore
  22. 2026-08-13 04:29 UTCEG score recompute
  23. 2026-08-13 04:29 UTCGHSA enrichment
  24. 2026-08-12 13:51 UTCEPSS rescore
  25. 2026-08-12 05:56 UTCEG score recompute
Show 29 more
  1. 2026-08-12 05:56 UTCGHSA enrichment
  2. 2026-08-11 07:23 UTCEG score recompute
  3. 2026-08-11 07:23 UTCGHSA enrichment
  4. 2026-08-11 00:00 UTCEPSS rescore
  5. 2026-08-10 08:50 UTCEG score recompute
  6. 2026-08-10 08:50 UTCGHSA enrichment
  7. 2026-08-09 13:47 UTCEPSS rescore
  8. 2026-08-09 10:17 UTCEG score recompute
  9. 2026-08-09 10:17 UTCGHSA enrichment
  10. 2026-08-08 16:37 UTCEPSS rescore
  11. 2026-08-08 11:44 UTCEG score recompute
  12. 2026-08-08 11:44 UTCGHSA enrichment
  13. 2026-08-07 13:11 UTCEG score recompute
  14. 2026-08-07 13:11 UTCGHSA enrichment
  15. 2026-08-06 16:32 UTCEG score recompute▲ 6.50
  16. 2026-08-06 16:32 UTCGHSA enrichment
  17. 2026-08-06 16:30 UTCNVD updateCVSS v3 → 6.5 · severity → MEDIUM
  18. 2026-08-06 16:06 UTCEG score recompute▼ 6.50
  19. 2026-08-06 16:06 UTCGHSA enrichment
  20. 2026-08-06 16:05 UTCNVD update
  21. 2026-08-06 15:32 UTCEG score recompute▲ 6.50
  22. 2026-08-06 15:32 UTCGHSA enrichment
  23. 2026-08-06 15:31 UTCMITRE cvelistV5CVSS v3 → 6.5 · severity → MEDIUM
  24. 2026-08-06 13:47 UTCEPSS rescore
  25. 2026-08-05 19:17 UTCEPSS rescore
  26. 2026-08-05 19:17 UTCEPSS rescore
  27. 2026-08-05 07:19 UTCNVD update
  28. 2026-08-05 06:20 UTCEG score recompute
  29. 2026-08-05 06:20 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-67553?
CVE-2026-67553 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-Dotnet: through 1.0.0. Users are recommended to upgrade to version 1.1.0, which fixes the issue.
When was CVE-2026-67553 disclosed?
CVE-2026-67553 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-2026-67553 actively exploited?
CVE-2026-67553 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 65.3% of all scored CVEs.
What is the CVSS score of CVE-2026-67553?
CVE-2026-67553 has a CVSS v3.1 base score of 6.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-67553?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-67553, 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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