CVE-2026-84961

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 96% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 4 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

A fix is available — apply it.

undici's BalancedPool constructor passes its entire options object through an internal deep-clone that serializes and reparses the value as JSON. Because JSON cannot represent functions, any function-valued TLS option, such as a caller-supplied checkServerIdentity callback or a custom connector inside the connect option, is silently discarded before it reaches the TLS layer. As a result a peer whose certificate the application's custom checkServerIdentity was written to reject, but which still passes Node's default hostname and chain checks, is accepted when reached through BalancedPool. The Client, Pool, and Agent dispatchers are not affected because they extract the connect and tls options before cloning. This affects undici versions from 7.24.1 up to 7.29.1 and from 8.0.0 up to 8.10.2, and only when the application supplies a function-valued connect or tls option to BalancedPool. Users should upgrade to undici 7.29.1 or 8.10.2.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: 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
Severity91% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

September 4, 2026

Last Modified

September 15, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
Patch available. Sources: github.
github Patch Available

undici vulnerable to TLS certificate validation bypass via dropped connect options in BalancedPool · Advisory · nodejs/undici · GitHub

https://github.com/nodejs/undici/security/advisories/GHSA-w293-vg96-wgc3
generic

Security Advisories | OpenJS Foundation CVE Numbering Authority

https://cna.openjsf.org/security-advisories.html

Vendor Advisories for CVE-2026-84961(2)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatnodejs26-main-26.8.2-0.1.hum12026-09-11redhat
redhatgrafana12-4-main-12.4.10-0.2.hum12026-09-09redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
node-undici5.15.0+dfsg1+~cs20.10.9.3-1 ... 8.9.0+dfsg+~cs3.2.0-1 (39 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
node-undici7.15.0+dfsg+~cs3.2.0-1 ... 8.9.0+dfsg+~cs3.2.0-1 (15 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
node-undici7.15.0+dfsg+~cs3.2.0-1 ... 8.9.0+dfsg+~cs3.2.0-1 (15 versions)——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 44× in last 7d / 64× 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. 2026-09-19 05:18 UTCVendor advisory
  2. 2026-09-19 01:21 UTCVendor advisory
  3. 2026-09-18 21:22 UTCEG score recompute
  4. 2026-09-18 21:22 UTCVendor advisory
  5. 2026-09-18 19:28 UTCEPSS rescore
  6. 2026-09-18 16:16 UTCVendor advisory
  7. 2026-09-18 12:14 UTCVendor advisory
  8. 2026-09-18 08:15 UTCVendor advisory
  9. 2026-09-18 04:18 UTCVendor advisory
  10. 2026-09-18 00:20 UTCVendor advisory
  11. 2026-09-17 20:22 UTCEG score recompute
  12. 2026-09-17 20:22 UTCVendor advisory
  13. 2026-09-17 19:32 UTCEPSS rescore
  14. 2026-09-17 14:54 UTCVendor advisory
  15. 2026-09-17 10:56 UTCVendor advisory
  16. 2026-09-17 06:58 UTCVendor advisory
  17. 2026-09-17 03:00 UTCVendor advisory
  18. 2026-09-16 22:31 UTCVendor advisory
  19. 2026-09-16 18:31 UTCVendor advisory
  20. 2026-09-16 14:34 UTCEG score recompute
  21. 2026-09-16 14:34 UTCVendor advisory
  22. 2026-09-16 14:09 UTCEPSS rescore
  23. 2026-09-16 10:36 UTCVendor advisory
  24. 2026-09-16 06:34 UTCEG score recompute
  25. 2026-09-16 06:34 UTCVendor advisory
Show 39 more
  1. 2026-09-16 05:15 UTCEPSS rescore
  2. 2026-09-16 02:37 UTCVendor advisory
  3. 2026-09-15 22:39 UTCVendor advisory
  4. 2026-09-15 18:41 UTCVendor advisory
  5. 2026-09-15 14:36 UTCEG score recompute▲ 1.70
  6. 2026-09-15 14:36 UTCVendor advisory
  7. 2026-09-15 14:31 UTCNVD updateCVSS v3 → 9.1 · severity → CRITICAL
  8. 2026-09-15 05:35 UTCEG score recompute
  9. 2026-09-15 05:35 UTCVendor advisory
  10. 2026-09-15 03:12 UTCEPSS rescore
  11. 2026-09-15 03:12 UTCEPSS rescore
  12. 2026-09-14 18:38 UTCVendor advisory
  13. 2026-09-14 07:31 UTCVendor advisory
  14. 2026-09-13 20:34 UTCEG score recompute
  15. 2026-09-13 20:34 UTCVendor advisory
  16. 2026-09-13 09:37 UTCVendor advisory
  17. 2026-09-12 22:39 UTCEG score recompute
  18. 2026-09-12 22:39 UTCVendor advisory
  19. 2026-09-12 11:41 UTCVendor advisory
  20. 2026-09-12 00:43 UTCEG score recompute
  21. 2026-09-12 00:43 UTCVendor advisory
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-11 14:53 UTCEPSS rescore
  24. 2026-09-11 13:46 UTCEG score recompute
  25. 2026-09-11 13:46 UTCVendor advisory
  26. 2026-09-11 02:47 UTCVendor advisory
  27. 2026-09-10 15:49 UTCEG score recompute
  28. 2026-09-10 15:49 UTCVendor advisory
  29. 2026-09-10 04:51 UTCVendor advisory
  30. 2026-09-08 01:35 UTCEG score recompute
  31. 2026-09-06 15:13 UTCEG score recompute
  32. 2026-09-06 13:48 UTCEPSS rescore
  33. 2026-09-05 17:16 UTCEG score recompute
  34. 2026-09-05 15:31 UTCEPSS rescore
  35. 2026-09-04 19:19 UTCEG score recompute
  36. 2026-09-04 18:49 UTCEG score recompute
  37. 2026-09-04 17:26 UTCEG score recompute
  38. 2026-09-04 16:55 UTCEG score recompute
  39. 2026-09-04 16:54 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-84961?
CVE-2026-84961 is a critical vulnerability published on September 4, 2026. undici's BalancedPool constructor passes its entire options object through an internal deep-clone that serializes and reparses the value as JSON. Because JSON cannot represent functions, any function-valued TLS option, such as a caller-supplied checkServerIdentity callback or a custom connector…
When was CVE-2026-84961 disclosed?
CVE-2026-84961 was first published in the National Vulnerability Database on September 4, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-84961 actively exploited?
CVE-2026-84961 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 95.7% of all scored CVEs.
What is the CVSS score of CVE-2026-84961?
CVE-2026-84961 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-84961?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84961, 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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