CVE-2026-89133

MEDIUMNVD 5.35.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 5.3 from GitHub Security Advisory published 2026-09-27. NVD baseline CVSS 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this week

Also known asEUVD-2026-87922 (ENISA EUVD) · GHSA-vrp7-vcfx-j447 (GitHub Security Advisories)Source: ENISA EUVD

5.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 5.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

wolfSSL versions 5.9.2 and earlier contain a flaw in the X.509 certificate validation logic where it fails to properly enforce NameConstraints extensions when there is an unconstrained CA tier between a name-constrained intermediate CA and the leaf certificate. wolfSSL incorrectly accepted certificates for hostnames they shouldn't be allowed to cover, due to a chain-walking state-machine bug that resets the validation state when encountering an intermediate without NameConstraints, thereby bypassing cryptographic delegation controls. This defect exists in the default build configuration that makes use of certificates where name constraint extensions are used. Thanks to Jack Lloyd, PathDiff, and Ben Smyth for reporting the issue.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
39
EG Risk 39/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity53% × 45%
Impact severity (EG Severity): CVSS 5.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.1% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.1%
EPSS %ILE
2nd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (5.3): severity, escalated by confirmed exploitation. This CVE's 5.3 is its impact severity (EG Severity), not escalated.

EG Severity
5.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-26). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

September 27, 2026

Last Modified

October 2, 2026

Advisory Details (1)

Auto-updated Sep 27, 2026
Patch available. Sources: github_pr.
GitHub pull request

Name Constraints cert chain walk

Fix merged in wolfSSL/wolfssl PR #10687 on 2026-07-01 — awaiting tagged release

https://github.com/wolfSSL/wolfssl/pull/10687

Vendor Advisories for CVE-2026-89133(2)

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:12(1)
PackageVulnerable rangeFix by version rangeDependents
wolfssl5.5.4-2 ... 5.9.2-1 (27 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
wolfssl5.7.2-0.1 ... 5.9.2-1 (14 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 59× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-11-01 16:36 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  4. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  5. 2026-10-27 12:31 UTCEG score recompute
  6. 2026-10-27 12:31 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  7. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  8. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  9. 2026-10-25 13:53 UTCEG score recompute
  10. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  11. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  12. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  13. 2026-10-22 12:32 UTCEG score recompute
  14. 2026-10-22 12:32 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  15. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  16. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  17. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  18. 2026-10-18 03:02 UTCEG score recompute
  19. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  20. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  21. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  22. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  23. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  24. 2026-10-12 14:49 UTCEG score recompute
  25. 2026-10-12 01:28 UTCVendor advisory
Show 57 more
  1. 2026-10-12 01:28 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  2. 2026-10-11 19:15 UTCEG score recompute
  3. 2026-10-11 16:32 UTCEG score recompute
  4. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  5. 2026-10-11 13:48 UTCEG score recompute
  6. 2026-10-11 00:38 UTCEG score recompute
  7. 2026-10-11 00:38 UTCVendor advisory
  8. 2026-10-11 00:37 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  10. 2026-10-09 23:49 UTCEG score recompute
  11. 2026-10-09 23:49 UTCVendor advisory
  12. 2026-10-09 23:49 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  13. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  14. 2026-10-08 23:09 UTCEG score recompute
  15. 2026-10-08 23:09 UTCVendor advisory
  16. 2026-10-08 23:09 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  17. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  18. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  19. 2026-10-07 22:28 UTCVendor advisory
  20. 2026-10-07 22:28 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  21. 2026-10-06 21:47 UTCEG score recompute
  22. 2026-10-06 21:47 UTCVendor advisory
  23. 2026-10-06 21:47 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  24. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  25. 2026-10-05 21:07 UTCEG score recompute
  26. 2026-10-05 21:07 UTCVendor advisory
  27. 2026-10-05 21:06 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  28. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  29. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  30. 2026-10-04 20:23 UTCVendor advisory
  31. 2026-10-04 20:22 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  32. 2026-10-03 19:40 UTCEG score recompute
  33. 2026-10-03 19:40 UTCVendor advisory
  34. 2026-10-03 19:40 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447 · GitHub CVSS 5.3
  35. 2026-10-02 19:00 UTCEG score recompute▼ 1.00
  36. 2026-10-02 19:00 UTCVendor advisory
  37. 2026-10-02 19:00 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447
  38. 2026-10-02 18:59 UTCNVD updateCVSS v3 → 5.3
  39. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  40. 2026-10-01 19:00 UTCVendor advisory
  41. 2026-10-01 19:00 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447
  42. 2026-09-30 18:17 UTCEG score recompute
  43. 2026-09-30 18:17 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447
  44. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  45. 2026-09-29 17:36 UTCEG score recompute
  46. 2026-09-29 17:36 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447
  47. 2026-09-29 16:45 UTCEG score recompute
  48. 2026-09-29 16:45 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447
  49. 2026-09-28 20:50 UTCEG score recompute
  50. 2026-09-28 20:50 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447
  51. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  52. 2026-09-28 11:00 UTCEG score recompute
  53. 2026-09-28 11:00 UTCGHSA enrichmentGHSA-vrp7-vcfx-j447
  54. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  55. 2026-09-27 10:20 UTCEG score recompute
  56. 2026-09-27 09:35 UTCEG score recomputeFirst assessed: 6.3 MEDIUM
  57. 2026-09-27 09:35 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-89133?
CVE-2026-89133 is a medium-severity vulnerability; its CVE record was published on September 27, 2026. wolfSSL versions 5.9.2 and earlier contain a flaw in the X.509 certificate validation logic where it fails to properly enforce NameConstraints extensions when there is an unconstrained CA tier between a name-constrained intermediate CA and the leaf certificate. wolfSSL incorrectly accepted…
When was CVE-2026-89133 made public?
CVE-2026-89133 was made public on September 26, 2026: that is the date its CVE record's CNA, wolfSSL Inc., gives for when the vulnerability was made public. The CVE record itself was published on September 27, 2026. EchelonGraph's copy of the record carries a last-modified date of October 2, 2026; the record at its source may have been updated since.
Is CVE-2026-89133 actively exploited?
CVE-2026-89133 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (2nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-89133?
CVE-2026-89133 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-89133?
A fix for CVE-2026-89133 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-89133 are linked in the Vendor Advisories panel on this page.

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