CVE-2026-67856

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.

An issue in open62541 v.1.5.5 and before allows a remote attacker to cause a denial of service via crafted CreateSubscription, CreateMonitoredItems(Sampling), Publish, TransferSubscriptions, and DeleteSubscriptions requests

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
38(Track)
EG Risk 38/100SSVC: 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%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
35%
KEV
Not listed

Published

August 4, 2026

Last Modified

August 5, 2026

Advisory Details (5)

Auto-updated Aug 5, 2026
No patch confirmed yet.
generic

heap-use-after-free in `TransferSubscriptions` / `DeleteSubscriptions` caused by stale `samplingMonitoredItems` back-pointers after shallow `UA_Subscription` copy · Issue #8092 · open62541/open62541 · GitHub

https://github.com/open62541/open62541/issues/8092
generic

open62541/src/server/ua_subscription.h at master · open62541/open62541 · GitHub

https://github.com/open62541/open62541/blob/master/src/server/ua_subscription.h
generic

open62541/src/server/ua_subscription.c at master · open62541/open62541 · GitHub

https://github.com/open62541/open62541/blob/master/src/server/ua_subscription.c
generic

open62541/src/server/ua_services_subscription.c at master · open62541/open62541 · GitHub

https://github.com/open62541/open62541/blob/master/src/server/ua_services_subscription.c
generic

open62541/examples/access_control/server_access_control.c at master · open62541/open62541 · GitHub

https://github.com/open62541/open62541/blob/master/examples/access_control/server_access_control.c

Vendor Advisories for CVE-2026-67856(1)

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

Affected Packages

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
open625411.4.11.1-1, 1.4.18-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
open625411.4.11.1-1, 1.4.18-1——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 26× in last 7d / 65× 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 04:18 UTCEG score recompute
  2. 2026-08-21 04:18 UTCGHSA enrichment
  3. 2026-08-20 22:56 UTCEPSS rescore
  4. 2026-08-20 15:36 UTCGHSA enrichment
  5. 2026-08-20 02:55 UTCEG score recompute
  6. 2026-08-20 02:55 UTCGHSA enrichment
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-19 14:13 UTCGHSA enrichment
  9. 2026-08-19 01:31 UTCEG score recompute
  10. 2026-08-19 01:31 UTCGHSA enrichment
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-18 12:49 UTCGHSA enrichment
  13. 2026-08-17 23:35 UTCEG score recompute
  14. 2026-08-17 23:35 UTCGHSA enrichment
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-17 10:53 UTCGHSA enrichment
  17. 2026-08-16 22:12 UTCEG score recompute
  18. 2026-08-16 22:12 UTCGHSA enrichment
  19. 2026-08-16 14:56 UTCEPSS rescore
  20. 2026-08-16 09:30 UTCEG score recompute
  21. 2026-08-16 09:30 UTCGHSA enrichment
  22. 2026-08-15 20:49 UTCGHSA enrichment
  23. 2026-08-15 08:07 UTCEG score recompute
  24. 2026-08-15 08:07 UTCGHSA enrichment
  25. 2026-08-15 01:30 UTCEPSS rescore
Show 40 more
  1. 2026-08-14 19:25 UTCGHSA enrichment
  2. 2026-08-14 06:44 UTCEG score recompute
  3. 2026-08-14 06:44 UTCGHSA enrichment
  4. 2026-08-13 22:00 UTCEPSS rescore
  5. 2026-08-13 18:02 UTCGHSA enrichment
  6. 2026-08-13 05:20 UTCGHSA enrichment
  7. 2026-08-12 16:36 UTCEG score recompute
  8. 2026-08-12 16:36 UTCGHSA enrichment
  9. 2026-08-12 13:51 UTCEPSS rescore
  10. 2026-08-12 03:52 UTCGHSA enrichment
  11. 2026-08-11 15:10 UTCEG score recompute
  12. 2026-08-11 15:10 UTCGHSA enrichment
  13. 2026-08-11 02:27 UTCEG score recompute
  14. 2026-08-11 02:27 UTCGHSA enrichment
  15. 2026-08-11 00:00 UTCEPSS rescore
  16. 2026-08-10 13:46 UTCGHSA enrichment
  17. 2026-08-10 01:04 UTCEG score recompute
  18. 2026-08-10 01:04 UTCGHSA enrichment
  19. 2026-08-09 13:47 UTCEPSS rescore
  20. 2026-08-09 12:23 UTCGHSA enrichment
  21. 2026-08-08 23:41 UTCEG score recompute
  22. 2026-08-08 23:41 UTCGHSA enrichment
  23. 2026-08-08 16:37 UTCEPSS rescore
  24. 2026-08-08 10:59 UTCGHSA enrichment
  25. 2026-08-07 22:17 UTCEG score recompute
  26. 2026-08-07 22:17 UTCGHSA enrichment
  27. 2026-08-07 09:35 UTCGHSA enrichment
  28. 2026-08-06 20:54 UTCEG score recompute
  29. 2026-08-06 20:54 UTCGHSA enrichment
  30. 2026-08-06 13:47 UTCEPSS rescore
  31. 2026-08-06 08:12 UTCEG score recompute
  32. 2026-08-06 08:12 UTCGHSA enrichment
  33. 2026-08-05 19:30 UTCEG score recompute▲ 7.50
  34. 2026-08-05 19:30 UTCGHSA enrichment
  35. 2026-08-05 19:30 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
  36. 2026-08-05 19:17 UTCEPSS rescore
  37. 2026-08-05 19:17 UTCEPSS rescore
  38. 2026-08-04 22:31 UTCNVD update
  39. 2026-08-04 21:43 UTCEG score recompute
  40. 2026-08-04 21:40 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-67856?
CVE-2026-67856 is a high vulnerability published on August 4, 2026. An issue in open62541 v.1.5.5 and before allows a remote attacker to cause a denial of service via crafted CreateSubscription, CreateMonitoredItems(Sampling), Publish, TransferSubscriptions, and DeleteSubscriptions requests
When was CVE-2026-67856 disclosed?
CVE-2026-67856 was first published in the National Vulnerability Database on August 4, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-67856 actively exploited?
CVE-2026-67856 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 64.5% of all scored CVEs.
What is the CVSS score of CVE-2026-67856?
CVE-2026-67856 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-67856?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-67856, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-67856

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