CVE-2026-65423

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-31. a secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.8Exploit: None knownExposed: 0

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

An integer overflow in the UA_Variant arrayDimensions product computation in open62541 may allow a remote attacker to trigger an out-of-bounds write.

CVSS v3
8.8
EG Score
8.8(high)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity88% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
46%
KEV
Not listed

Published

July 30, 2026

Last Modified

July 31, 2026

Advisory Details (7)

Auto-updated Jul 30, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: github_pr, cisa.
generic

CSAF/csaf_files/OT/white/2026/icsa-26-211-08.json at develop · cisagov/CSAF · GitHub

https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-08.json
cisa Patch Available🔴 Active Exploitation

o6 Automation open62541 | CISA

o6 Automation open62541 | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-08
github_pr Patch Available

fix(server): migrate samplingMonitoredItems in TransferSubscriptions

Patch available: open62541/open62541 v1.3.19 (PR #8238 merged 2026-07-23)

https://github.com/open62541/open62541/pull/8238/commits/afab4107bfd161da9ce8bb30ed77f3968c9c97df
github_pr Patch Available

fix(pubsub): check message length before signature size subtraction

Patch available: open62541/open62541 v1.5.6 (PR #8237 merged 2026-07-24)

https://github.com/open62541/open62541/pull/8237/commits/1b71d9c5d9c4d02d4729b8903a52e9f530bf804e
github_pr Patch Available

fix(pubsub): check message length before signature size subtraction

Patch available: open62541/open62541 v1.3.19 (PR #8236 merged 2026-07-23)

https://github.com/open62541/open62541/pull/8236/commits/06b99fef667c8ec5bdf0605b4f00c84fcc1d3a60
github_pr Patch Available

fix(core): reject overflowing arrayDimensions product in Variant en/d…

Patch available: open62541/open62541 v1.3.19 (PR #8235 merged 2026-07-23)

https://github.com/open62541/open62541/pull/8235/commits/b666d35769ce63998442e4d0810a3fb10b50179f
generic

Contact | o6 Automation Website

https://www.o6-automation.com/contact

Vendor Advisories for CVE-2026-65423(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 25× in last 7d / 83× 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 22:55 UTCEPSS rescore
  2. 2026-08-20 21:28 UTCGHSA enrichment
  3. 2026-08-20 08:44 UTCGHSA enrichment
  4. 2026-08-19 20:00 UTCEG score recompute
  5. 2026-08-19 20:00 UTCGHSA enrichment
  6. 2026-08-19 17:04 UTCEPSS rescore
  7. 2026-08-19 07:16 UTCGHSA enrichment
  8. 2026-08-18 18:27 UTCEG score recompute
  9. 2026-08-18 18:27 UTCGHSA enrichment
  10. 2026-08-18 13:48 UTCEPSS rescore
  11. 2026-08-18 05:31 UTCGHSA enrichment
  12. 2026-08-17 16:33 UTCEG score recompute
  13. 2026-08-17 16:33 UTCGHSA enrichment
  14. 2026-08-17 13:47 UTCEPSS rescore
  15. 2026-08-17 03:37 UTCEG score recompute
  16. 2026-08-17 03:37 UTCGHSA enrichment
  17. 2026-08-16 14:56 UTCEPSS rescore
  18. 2026-08-16 14:53 UTCEG score recompute
  19. 2026-08-16 14:53 UTCGHSA enrichment
  20. 2026-08-16 02:09 UTCGHSA enrichment
  21. 2026-08-15 13:26 UTCEG score recompute
  22. 2026-08-15 13:26 UTCGHSA enrichment
  23. 2026-08-15 01:30 UTCEPSS rescore
  24. 2026-08-15 00:42 UTCGHSA enrichment
  25. 2026-08-14 11:58 UTCGHSA enrichment
Show 58 more
  1. 2026-08-13 23:14 UTCEG score recompute
  2. 2026-08-13 23:14 UTCGHSA enrichment
  3. 2026-08-13 22:00 UTCEPSS rescore
  4. 2026-08-13 10:30 UTCGHSA enrichment
  5. 2026-08-12 21:45 UTCEG score recompute
  6. 2026-08-12 21:45 UTCGHSA enrichment
  7. 2026-08-12 13:51 UTCEPSS rescore
  8. 2026-08-12 09:01 UTCGHSA enrichment
  9. 2026-08-11 20:17 UTCEG score recompute
  10. 2026-08-11 20:17 UTCGHSA enrichment
  11. 2026-08-11 07:33 UTCEG score recompute
  12. 2026-08-11 07:33 UTCGHSA enrichment
  13. 2026-08-11 00:00 UTCEPSS rescore
  14. 2026-08-10 18:49 UTCGHSA enrichment
  15. 2026-08-10 06:05 UTCGHSA enrichment
  16. 2026-08-09 17:21 UTCEG score recompute
  17. 2026-08-09 17:21 UTCGHSA enrichment
  18. 2026-08-09 13:47 UTCEPSS rescore
  19. 2026-08-09 04:37 UTCEG score recompute
  20. 2026-08-09 04:37 UTCGHSA enrichment
  21. 2026-08-08 16:37 UTCEPSS rescore
  22. 2026-08-08 15:53 UTCGHSA enrichment
  23. 2026-08-08 03:08 UTCEG score recompute
  24. 2026-08-08 03:08 UTCGHSA enrichment
  25. 2026-08-07 14:24 UTCGHSA enrichment
  26. 2026-08-07 01:40 UTCEG score recompute
  27. 2026-08-07 01:40 UTCGHSA enrichment
  28. 2026-08-06 13:47 UTCEPSS rescore
  29. 2026-08-06 12:56 UTCGHSA enrichment
  30. 2026-08-06 00:12 UTCEG score recompute
  31. 2026-08-06 00:12 UTCGHSA enrichment
  32. 2026-08-05 19:17 UTCEPSS rescore
  33. 2026-08-05 19:17 UTCEPSS rescore
  34. 2026-08-05 11:28 UTCGHSA enrichment
  35. 2026-08-04 22:39 UTCEG score recompute
  36. 2026-08-04 22:39 UTCGHSA enrichment
  37. 2026-08-04 15:10 UTCEPSS rescore
  38. 2026-08-04 10:39 UTCEPSS rescore
  39. 2026-08-04 09:55 UTCGHSA enrichment
  40. 2026-08-03 20:49 UTCEG score recompute
  41. 2026-08-03 20:49 UTCGHSA enrichment
  42. 2026-08-03 10:36 UTCEPSS rescore
  43. 2026-08-03 08:04 UTCGHSA enrichment
  44. 2026-08-02 19:20 UTCGHSA enrichment
  45. 2026-08-02 06:36 UTCEG score recompute
  46. 2026-08-02 06:36 UTCGHSA enrichment
  47. 2026-08-02 02:27 UTCEPSS rescore
  48. 2026-08-01 17:52 UTCGHSA enrichment
  49. 2026-08-01 05:08 UTCEG score recompute
  50. 2026-08-01 05:08 UTCGHSA enrichment
  51. 2026-08-01 04:16 UTCEPSS rescore
  52. 2026-07-31 16:24 UTCEG score recompute
  53. 2026-07-31 16:24 UTCGHSA enrichment
  54. 2026-07-31 12:05 UTCEG score recompute
  55. 2026-07-31 12:05 UTCGHSA enrichment
  56. 2026-07-30 23:20 UTCEG score recompute
  57. 2026-07-30 22:21 UTCEG score recompute
  58. 2026-07-30 22:20 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-65423?
CVE-2026-65423 is a high vulnerability published on July 30, 2026. An integer overflow in the UA_Variant arrayDimensions product computation in open62541 may allow a remote attacker to trigger an out-of-bounds write.
When was CVE-2026-65423 disclosed?
CVE-2026-65423 was first published in the National Vulnerability Database on July 30, 2026, with the most recent update on July 31, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-65423 actively exploited?
CVE-2026-65423 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 53.6% of all scored CVEs.
What is the CVSS score of CVE-2026-65423?
CVE-2026-65423 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-65423?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-65423, 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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