CVE-2026-12151

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.8%, top 48% 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, secondary
Trending — Patch released this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

Impact: The undici WebSocket client enforces maxPayloadSize on the cumulative byte count of fragments in a message but does not enforce a limit on the number of fragments. A malicious WebSocket server can stream many small or empty continuation frames that each pass per-frame and cumulative-size validation, collectively causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service.

Affected applications are those using the undici WebSocket client (new WebSocket(...)) or the WebSocketStream API that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint.

All releases starting at undici 6.17.0 are affected.

Patches: Upgrade to undici >= 6.26.0, >= 7.28.0, or >= 8.5.0. Workarounds: No workaround is available. The fix must be applied through an upgrade.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
52.4%
KEV
Not listed

Published

June 17, 2026

Last Modified

July 21, 2026

Advisory Details (2)

Auto-updated Jun 17, 2026
Patch available. Sources: github.
github Patch Available

undici WebSocket client vulnerable to denial of service via fragment count bypass · Advisory · nodejs/undici · GitHub

https://github.com/nodejs/undici/security/advisories/GHSA-vxpw-j846-p89q
generic

Security Advisories | OpenJS Foundation CVE Numbering Authority

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

Vendor Advisories for CVE-2026-12151(15)

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

Patch Availability(12)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatopenshift4/ose-monitoring-plugin-rhel9:17833063962026-07-16redhat
redhatnodejs:24-8100020260630152626.6d8804032026-07-15redhat
redhatnodejs22-1:22.23.1-2.el10_02026-07-14redhat
redhatnodejs24-main-24.18.0-0.3.hum12026-07-11redhat
redhatnodejs26-main-26.5.0-1.3.hum12026-07-10redhat
redhatdevspaces/pluginregistry-rhel9:17829893672026-07-08redhat
redhatrhdh/rhdh-hub-rhel9:17834481842026-07-08redhat
redhatnodejs:24-9080020260626074955.rhel92026-07-06redhat
redhatnodejs22-1:22.23.1-2.el10_22026-07-06redhat
redhatnodejs24-1:24.18.0-1.el10_22026-07-06redhat
redhatnodejs:22-9080020260626075442.rhel92026-07-06redhat
redhatcluster-observability-operator/troubleshooting-panel-console-plugin-rhel9:17828394942026-07-01redhat

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

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
undici—8.5.0—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× 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.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:30 UTCEPSS rescore
  5. 2026-07-19 02:28 UTCEPSS rescore
  6. 2026-07-18 10:04 UTCEPSS rescore
  7. 2026-07-16 21:43 UTCVendor advisory
  8. 2026-07-16 17:02 UTCEPSS rescore
  9. 2026-07-16 05:28 UTCVendor advisory
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 16:26 UTCVendor advisory
  12. 2026-07-15 03:25 UTCVendor advisory
  13. 2026-07-15 02:00 UTCEPSS rescore
  14. 2026-07-14 14:20 UTCVendor advisory
  15. 2026-07-14 01:20 UTCVendor advisory
  16. 2026-07-13 22:30 UTCEPSS rescore
  17. 2026-07-13 12:19 UTCVendor advisory
  18. 2026-07-13 06:12 UTCEPSS rescore
  19. 2026-07-12 23:18 UTCVendor advisory
  20. 2026-07-12 10:16 UTCVendor advisory
  21. 2026-07-12 05:46 UTCEPSS rescore
  22. 2026-07-11 21:16 UTCVendor advisory
  23. 2026-07-11 08:27 UTCEPSS rescore
  24. 2026-07-11 08:16 UTCVendor advisory
  25. 2026-07-10 19:16 UTCVendor advisory
Show 45 more
  1. 2026-07-10 06:16 UTCVendor advisory
  2. 2026-07-09 19:10 UTCEPSS rescore
  3. 2026-07-09 17:04 UTCVendor advisory
  4. 2026-07-09 02:21 UTCVendor advisory
  5. 2026-07-08 15:15 UTCEPSS rescore
  6. 2026-07-08 15:15 UTCEPSS rescore
  7. 2026-07-08 13:20 UTCVendor advisory
  8. 2026-07-08 00:19 UTCVendor advisory
  9. 2026-07-07 13:46 UTCEPSS rescore
  10. 2026-07-07 11:18 UTCVendor advisory
  11. 2026-07-06 21:48 UTCVendor advisory
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 06:36 UTCVendor advisory
  14. 2026-07-06 02:23 UTCEPSS rescore
  15. 2026-07-05 17:36 UTCVendor advisory
  16. 2026-07-05 04:35 UTCVendor advisory
  17. 2026-07-05 02:30 UTCEPSS rescore
  18. 2026-07-05 02:30 UTCEPSS rescore
  19. 2026-07-04 15:22 UTCVendor advisory
  20. 2026-07-04 06:31 UTCEPSS rescore
  21. 2026-07-04 02:11 UTCVendor advisory
  22. 2026-07-03 13:10 UTCVendor advisory
  23. 2026-07-03 00:09 UTCVendor advisory
  24. 2026-07-02 11:09 UTCVendor advisory
  25. 2026-07-01 15:06 UTCEPSS rescore
  26. 2026-07-01 15:06 UTCEPSS rescore
  27. 2026-06-30 23:22 UTCEPSS rescore
  28. 2026-06-29 14:06 UTCEPSS rescore
  29. 2026-06-28 14:07 UTCEPSS rescore
  30. 2026-06-28 04:56 UTCEPSS rescore
  31. 2026-06-28 04:56 UTCEPSS rescore
  32. 2026-06-27 03:08 UTCEPSS rescore
  33. 2026-06-25 13:49 UTCEPSS rescore
  34. 2026-06-24 14:05 UTCEPSS rescore
  35. 2026-06-23 21:32 UTCEPSS rescore
  36. 2026-06-22 14:25 UTCEPSS rescore
  37. 2026-06-22 14:25 UTCEPSS rescore
  38. 2026-06-21 14:56 UTCEPSS rescore
  39. 2026-06-21 14:56 UTCEPSS rescore
  40. 2026-06-21 01:59 UTCEPSS rescore
  41. 2026-06-21 01:59 UTCEPSS rescore
  42. 2026-06-19 19:25 UTCEPSS rescore
  43. 2026-06-18 17:52 UTCEPSS rescore
  44. 2026-06-17 17:53 UTCEG score recompute
  45. 2026-06-17 17:52 UTCNVD updatefirst tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-12151?
CVE-2026-12151 is a high vulnerability published on June 17, 2026. Impact: The undici WebSocket client enforces maxPayloadSize on the cumulative byte count of fragments in a message but does not enforce a limit on the number of fragments. A malicious WebSocket server can stream many small or empty continuation frames that each pass per-frame and cumulative-size…
When was CVE-2026-12151 disclosed?
CVE-2026-12151 was first published in the National Vulnerability Database on June 17, 2026, with the most recent update on July 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12151 actively exploited?
CVE-2026-12151 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 52.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-12151?
CVE-2026-12151 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-12151?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12151, 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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