CVE-2026-3833

HIGHNVD 7.47.4—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.4 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 55% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Trending — Patch released this weekElevated
7.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.4Exploit: Elevated riskExposed: 0

A fix is available — apply it.

A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of nameConstraints labels, specifically for dNSName (DNS) or rfc822Name (email) constraints within excludedSubtrees or permittedSubtrees. A remote attacker can exploit this by crafting a leaf certificate with casing differences in the Subject Alternative Name (SAN), leading to a policy bypass where a certificate that should be rejected is instead accepted. This could result in unauthorized access or information disclosure.

CVSS v3
7.4
EG Score
7.4(medium)
EG Risk
64(Attend)
EG Risk 64/100SSVC: Attend

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
Severity74% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
46%
KEV
Not listed

Published

April 30, 2026

Last Modified

September 17, 2026

Advisory Details (3)

Auto-updated Apr 30, 2026
🔬 Proof of concept available. Patch available. Sources: redhat.
generic🟡 PoC Available

[Moderate] gnutls x509 nameconstraints: excluded dns/email subtree bypass via case-sensitive comparison (security report) (#1803) · Issues · gnutls / GnuTLS · GitLab

https://gitlab.com/gnutls/gnutls/-/issues/1803
redhat

2445763 – (CVE-2026-3833) CVE-2026-3833 gnutls: GnuTLS: Policy bypass due to case-sensitive nameConstraints comparison

https://bugzilla.redhat.com/show_bug.cgi?id=2445763
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-3833

Vendor Advisories for CVE-2026-3833(20)

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

Patch Availability(23)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhcos-418.94.202609031320-02026-09-17redhat
ubuntulibgnutlsxx28 (3.4.10-4ubuntu1.9+esm3) @ xenial2026-09-17ubuntu
ubuntulibgnutls30t64 (3.8.12-2ubuntu1.1) @ resolute2026-09-17ubuntu
redhatrhcos-414.92.202609011250-02026-09-14redhat
redhatrhcos-416.94.202609011112-02026-09-10redhat
redhatrhcos-412.86.202608241157-02026-09-03redhat
redhatrhcos-417.94.202608250221-02026-09-03redhat
redhatrhcos-4.19.9.6.202608182320-02026-08-26redhat
redhatrhui5/rhua-tp-rhel9:17872412602026-08-24redhat
redhatgnutls-0:3.3.29-9.el7_9.22026-07-22redhat
redhatgnutls-0:3.7.6-21.el9_2.72026-07-20redhat
redhatgnutls-0:3.8.3-4.el9_4.62026-06-29redhat
redhatlibtasn1-0:4.13-4.el8_8.12026-06-29redhat
redhatlibtasn1-0:4.13-3.el8_6.22026-06-29redhat
redhatlibtasn1-0:4.13-3.el8_4.12026-06-29redhat
redhatgnutls-0:3.8.3-6.el9_6.42026-06-25redhat
redhatdiscovery/discovery-ui-rhel9:17821669522026-06-24redhat
redhatrhui5/rhua-rhel9:17815257392026-06-16redhat
redhatgnutls-0:3.8.9-9.el10_0.192026-06-16redhat
redhatgnutls-0:3.6.16-8.el8_10.62026-05-26redhat
redhatgnutls-0:3.8.10-4.el9_82026-05-26redhat
redhatgnutls-0:3.8.10-4.el10_22026-05-26redhat
redhatgnutls-main-3.8.13-1.hum12026-05-02redhat

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

(9 across 9 ecosystems)
Alpine:v3.20(1)
PackageVulnerable rangeFixed inDependents
gnutls—3.8.13-r0—
Alpine:v3.21(1)
PackageVulnerable rangeFixed inDependents
gnutls—3.8.13-r0—
Alpine:v3.22(1)
PackageVulnerable rangeFixed inDependents
gnutls—3.8.13-r0—
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
gnutls—3.8.13-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
gnutls—3.8.13-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
gnutls283.7.1-5 ... 3.7.1-5+deb11u9 (10 versions)3.7.1-5+deb11u10—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
gnutls283.7.9-2 ... 3.7.9-2+deb12u6 (7 versions)3.7.9-2+deb12u7—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
gnutls283.8.9-3, 3.8.9-3+deb13u1, 3.8.9-3+deb13u2, 3.8.9-3+deb13u33.8.9-3+deb13u4—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
gnutls283.8.10-1 ... 3.8.9-3 (11 versions)3.8.13-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(5)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 22× in last 7d / 77× 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 285 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-3833?
CVE-2026-3833 is a high vulnerability published on April 30, 2026. A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of nameConstraints labels, specifically for dNSName (DNS) or rfc822Name (email) constraints within excludedSubtrees or permittedSubtrees. A remote attacker can exploit this by crafting a leaf…
When was CVE-2026-3833 disclosed?
CVE-2026-3833 was first published in the National Vulnerability Database on April 30, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-3833 actively exploited?
CVE-2026-3833 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 54.3% of all scored CVEs.
What is the CVSS score of CVE-2026-3833?
CVE-2026-3833 has a CVSS v3 base score of 7.4 (NVD).
How do I remediate CVE-2026-3833?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-3833, 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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