CVE-2026-9675

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: 0.4%, top 64% 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
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Impact: The undici WebSocket client enforces maxPayloadSize per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can stream many small fragments that each pass per-frame validation but collectively exceed the configured limit, 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(...)) that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint.

This is a regression specific to undici 8.1.0. The 6.25.0 line shipped the equivalent cumulative check from the start and is unaffected. The 7.x line never had the maxPayloadSize feature and is also unaffected.

Patches: Upgrade to undici >= 8.5.0.

Workarounds: No workaround is available. The fix must be applied through an upgrade.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
38
EG Risk 38/100

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%
EPSS PROB
0.5%
EPSS %ILE
39th
KEV
Not listed

Published

June 17, 2026

Last Modified

June 25, 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 cumulative fragment bypass · Advisory · nodejs/undici · GitHub

https://github.com/nodejs/undici/security/advisories/GHSA-38rv-x7px-6hhq
generic

Security Advisories | OpenJS Foundation CVE Numbering Authority

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

Vendor Advisories for CVE-2026-9675(6)

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

Patch Availability(4)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatnodejs24-main-24.16.0-1.hum12026-06-13redhat
redhatrust-main-1.96.0-1.hum12026-06-03redhat
redhatnodejs26-main-26.3.0-1.2.hum12026-06-02redhat
redhatnodejs25-main-25.9.0-1.1.hum12026-04-10redhat

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 rangeFix by version rangeDependents
undici—
  • 8.0.0 up to 8.5.0: fixed in 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 / 33× 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.

Showing the most recent 100 of 242 total refreshes for this CVE.

  1. 2026-10-04 23:23 UTCEPSS rescore
  2. 2026-10-03 14:26 UTCEPSS rescore
  3. 2026-10-03 06:09 UTCOSV refresh
  4. 2026-10-02 17:57 UTCEPSS rescore
  5. 2026-10-01 19:51 UTCEPSS rescore
  6. 2026-09-30 15:04 UTCEPSS rescore
  7. 2026-09-29 15:24 UTCEPSS rescore
  8. 2026-09-28 13:52 UTCEPSS rescore
  9. 2026-09-28 13:52 UTCEPSS rescore
  10. 2026-09-27 13:49 UTCEPSS rescore
  11. 2026-09-26 15:59 UTCEPSS rescore
  12. 2026-09-24 14:04 UTCEPSS rescore
  13. 2026-09-23 17:54 UTCEPSS rescore
  14. 2026-09-22 16:01 UTCEPSS rescore
  15. 2026-09-21 21:09 UTCEPSS rescore
  16. 2026-09-20 20:16 UTCEPSS rescore
  17. 2026-09-18 19:28 UTCEPSS rescore
  18. 2026-09-17 19:32 UTCEPSS rescore
  19. 2026-09-16 14:09 UTCEPSS rescore
  20. 2026-09-16 05:15 UTCEPSS rescore
  21. 2026-09-15 03:12 UTCEPSS rescore
  22. 2026-09-14 03:07 UTCEG score recompute
  23. 2026-09-14 03:07 UTCVendor advisory
  24. 2026-09-13 16:48 UTCEPSS rescore
  25. 2026-09-13 14:13 UTCEG score recompute
Show 75 more
  1. 2026-09-13 14:13 UTCVendor advisory
  2. 2026-09-12 15:02 UTCEPSS rescore
  3. 2026-09-11 14:53 UTCEPSS rescore
  4. 2026-09-11 09:38 UTCEPSS rescore
  5. 2026-09-10 09:35 UTCEPSS rescore
  6. 2026-09-08 22:01 UTCEPSS rescore
  7. 2026-09-06 13:48 UTCEPSS rescore
  8. 2026-09-05 15:31 UTCEPSS rescore
  9. 2026-09-04 05:07 UTCEPSS rescore
  10. 2026-09-02 14:12 UTCEPSS rescore
  11. 2026-09-01 13:54 UTCEPSS rescore
  12. 2026-09-01 04:40 UTCEPSS rescore
  13. 2026-08-30 21:20 UTCEG score recompute
  14. 2026-08-30 21:20 UTCVendor advisory
  15. 2026-08-30 19:18 UTCEPSS rescore
  16. 2026-08-30 01:22 UTCEPSS rescore
  17. 2026-08-28 21:42 UTCEPSS rescore
  18. 2026-08-27 14:25 UTCEPSS rescore
  19. 2026-08-26 14:47 UTCEPSS rescore
  20. 2026-08-25 13:49 UTCEPSS rescore
  21. 2026-08-24 22:24 UTCEG score recompute
  22. 2026-08-24 22:24 UTCVendor advisory
  23. 2026-08-24 14:18 UTCEPSS rescore
  24. 2026-08-24 06:50 UTCVendor advisory
  25. 2026-08-23 16:53 UTCVendor advisory
  26. 2026-08-23 04:15 UTCEG score recompute
  27. 2026-08-23 04:15 UTCVendor advisory
  28. 2026-08-23 00:19 UTCEPSS rescore
  29. 2026-08-21 23:49 UTCEPSS rescore
  30. 2026-08-21 22:31 UTCVendor advisory
  31. 2026-08-21 09:31 UTCEG score recompute
  32. 2026-08-21 09:31 UTCVendor advisory
  33. 2026-08-20 22:56 UTCEPSS rescore
  34. 2026-08-20 20:52 UTCVendor advisory
  35. 2026-08-20 08:13 UTCEG score recompute
  36. 2026-08-20 08:13 UTCVendor advisory
  37. 2026-08-19 17:04 UTCEPSS rescore
  38. 2026-08-19 08:10 UTCEG score recompute
  39. 2026-08-19 08:10 UTCVendor advisory
  40. 2026-08-18 13:49 UTCEPSS rescore
  41. 2026-08-17 14:21 UTCEG score recompute
  42. 2026-08-17 14:21 UTCVendor advisory
  43. 2026-08-17 13:47 UTCEPSS rescore
  44. 2026-08-17 01:41 UTCEG score recompute
  45. 2026-08-17 01:41 UTCVendor advisory
  46. 2026-08-16 14:56 UTCEPSS rescore
  47. 2026-08-16 13:02 UTCEG score recompute
  48. 2026-08-16 13:02 UTCVendor advisory
  49. 2026-08-16 02:15 UTCEPSS rescore
  50. 2026-08-16 00:24 UTCVendor advisory
  51. 2026-08-15 11:45 UTCEG score recompute
  52. 2026-08-15 11:45 UTCVendor advisory
  53. 2026-08-15 01:31 UTCEPSS rescore
  54. 2026-08-14 23:06 UTCVendor advisory
  55. 2026-08-14 10:28 UTCEG score recompute
  56. 2026-08-14 10:28 UTCVendor advisory
  57. 2026-08-13 22:00 UTCEPSS rescore
  58. 2026-08-13 21:49 UTCVendor advisory
  59. 2026-08-13 08:47 UTCVendor advisory
  60. 2026-08-12 20:07 UTCEG score recompute
  61. 2026-08-12 20:07 UTCVendor advisory
  62. 2026-08-12 13:51 UTCEPSS rescore
  63. 2026-08-12 07:29 UTCVendor advisory
  64. 2026-08-11 18:50 UTCEG score recompute
  65. 2026-08-11 18:50 UTCVendor advisory
  66. 2026-08-11 13:43 UTCEPSS rescore
  67. 2026-08-11 06:12 UTCEG score recompute
  68. 2026-08-11 06:12 UTCVendor advisory
  69. 2026-08-11 00:00 UTCEPSS rescore
  70. 2026-08-10 17:33 UTCVendor advisory
  71. 2026-08-10 03:09 UTCVendor advisory
  72. 2026-08-09 14:30 UTCEG score recompute
  73. 2026-08-09 14:30 UTCVendor advisory
  74. 2026-08-09 13:47 UTCEPSS rescore
  75. 2026-08-09 01:52 UTCEG score recompute

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Frequently asked(5)

What is CVE-2026-9675?
CVE-2026-9675 is a high vulnerability published on June 17, 2026. Impact: The undici WebSocket client enforces maxPayloadSize per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can stream many small fragments that each pass per-frame validation but collectively exceed the configured limit, causing…
When was CVE-2026-9675 disclosed?
CVE-2026-9675 was first published on June 17, 2026, with the most recent update on June 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-9675 actively exploited?
CVE-2026-9675 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-9675?
CVE-2026-9675 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-9675?
A fix for CVE-2026-9675 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-9675 are linked in the Vendor Advisories panel on this page.

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