CVE-2026-3833

HIGHNVD 7.47.4—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.4 under NVD CVSS v3. EPSS exploit probability: 0.9% (58th percentile of EPSS-scored CVEs). GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Trending — 4 sources updated 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: 0.9%CVSS: 7.4Exploit: Elevated riskExposed services: Not assessed

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
7.4HIGHmedium confidence
EG Risk
64
EG Risk 64/100CISA SSVC

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%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
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
0.9%
EPSS %ILE
58th
KEV
Not listed

CISA SSVCTrack 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 public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

April 30, 2026

Last Modified

October 9, 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
redhatMentions a patch (unverified)

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(27)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibgnutlsxx28 (3.6.13-2ubuntu1.12+esm2) @ focal2026-10-09ubuntu
ubuntulibgnutls30t64 (3.8.12-2ubuntu1.1) @ resolute2026-10-09ubuntu
redhatrhai/base-image-neuron-rhel9:17907035422026-10-01redhat
redhatopenshift/ose-rhel-coreos-9:415.92.202609140326-02026-09-28redhat
redhatcert-manager/cert-manager-trust-manager-rhel9:17905985932026-09-28redhat
redhatopenshift/ose-rhel-coreos-9:418.94.202609031320-02026-09-17redhat
redhatopenshift/ose-rhel-coreos-9:413.92.202609080414-02026-09-17redhat
redhatopenshift/ose-rhel-coreos-9:414.92.202609011250-02026-09-14redhat
redhatopenshift/ose-rhel-coreos-9:416.94.202609011112-02026-09-10redhat
redhatopenshift/ose-rhel-coreos-9:417.94.202608250221-02026-09-03redhat
redhatopenshift/ose-rhel-coreos-8:412.86.202608241157-02026-09-03redhat
redhatopenshift/ose-rhel-coreos-9:4.19.9.6.202608182320-02026-08-26redhat
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
redhatlibtasn1-0:4.13-3.el8_6.22026-06-29redhat
redhatlibtasn1-0:4.13-4.el8_8.12026-06-29redhat
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 rangeFix by version rangeDependents
gnutls—
  • every version up to 3.8.13-r0: fixed in 3.8.13-r0
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
gnutls—
  • every version up to 3.8.13-r0: fixed in 3.8.13-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
gnutls—
  • every version up to 3.8.13-r0: fixed in 3.8.13-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
gnutls—
  • every version up to 3.8.13-r0: fixed in 3.8.13-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
gnutls—
  • every version up to 3.8.13-r0: fixed in 3.8.13-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
gnutls283.7.1-5 ... 3.7.1-5+deb11u9 (10 versions)
  • every version up to 3.7.1-5+deb11u10: fixed in 3.7.1-5+deb11u10
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
gnutls283.7.9-2 ... 3.7.9-2+deb12u6 (7 versions)
  • every version up to 3.7.9-2+deb12u7: fixed in 3.7.9-2+deb12u7
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
gnutls283.8.9-3, 3.8.9-3+deb13u1, 3.8.9-3+deb13u2, 3.8.9-3+deb13u3
  • every version up to 3.8.9-3+deb13u4: fixed in 3.8.9-3+deb13u4
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
gnutls283.8.10-1 ... 3.8.9-3 (11 versions)
  • every version up to 3.8.13-1: fixed in 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 12× in last 7d / 62× 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 323 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

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 on April 30, 2026, with the most recent update on October 9, 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 0.9% probability of exploitation in the next 30 days (58th percentile of EPSS-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?
A fix for CVE-2026-3833 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-3833 are linked in the Vendor Advisories panel on this page.

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