CVE-2026-3833

HIGHNVD 7.47.4
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.4 under NVD CVSS v3. EPSS exploit probability: 0.6% (46th percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 6.5 is lower than this score; a lower GitHub score revises it only when its advisory is newer than the CVE record's last change, and this advisory (published 2026-04-30) is not newer than that change (2026-10-26), so it does not.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this weekElevated

Also known asEUVD-2026-26403 (ENISA EUVD) · GHSA-6rgh-57xm-37v8 (GitHub Security Advisories)Source: ENISA EUVD

7.4EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 7.4Exploit: No code on recordExposed 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 64/100

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)
Severity74% × 45%
Impact severity (EG Severity): CVSS 7.4 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
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 public PoC (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
0.6%
EPSS %ILE
46th
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 (7.4): severity, escalated by confirmed exploitation. This CVE's 7.4 is its impact severity (EG Severity), not escalated.

EG Severity
7.4 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.6% 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 public PoC (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

April 30, 2026

Last Modified

October 26, 2026

Advisory Details (3)

Auto-updated Apr 30, 2026
Patch available. Sources: redhat.
Web page

[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
Red Hat

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
Red HatMentions a patch (unverified)

cve-details

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

Patch Availability(30)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatcert-manager/cert-manager-operator-bundle:17919704842026-10-14redhat
redhatcert-manager/cert-manager-operator-bundle:17919662592026-10-14redhat
redhatcert-manager/jetstack-cert-manager-rhel9:17913710692026-10-13redhat
redhatcert-manager/cert-manager-operator-rhel9:17917882872026-10-13redhat
redhatcert-manager/jetstack-cert-manager-rhel9:17914597112026-10-13redhat
redhatcert-manager/cert-manager-operator-rhel9:17890290762026-10-13redhat
redhatcert-manager/cert-manager-istio-csr-rhel9:17914597592026-10-13redhat
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
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-0:3.8.3-4.el9_4.62026-06-29redhat
redhatgnutls-0:3.8.3-6.el9_6.42026-06-25redhat
redhatdiscovery/discovery-ui-rhel9:17821669522026-06-24redhat
redhatgnutls-0:3.8.9-9.el10_0.192026-06-16redhat
redhatrhui5/rhua-rhel9:17815257392026-06-16redhat
redhatgnutls-0:3.6.16-8.el8_10.62026-05-26redhat
redhatgnutls-0:3.8.10-4.el9_82026-05-26redhat

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

(12)

Data Freshness Timeline

(refreshed 10× in last 7d / 57× 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.

Showing the most recent 99 of 367 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 268 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  2. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  3. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  4. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  5. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  6. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  7. 2026-10-26 21:32 UTCEG score recompute
  8. 2026-10-26 21:32 UTCVendor advisory
  9. 2026-10-26 21:31 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  10. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  11. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  12. 2026-10-25 14:32 UTCEG score recompute
  13. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  14. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  15. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  16. 2026-10-22 09:08 UTCEG score recompute
  17. 2026-10-22 09:08 UTCVendor advisory
  18. 2026-10-22 09:08 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  19. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  20. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  21. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  22. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  23. 2026-10-18 03:44 UTCEG score recompute
  24. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  25. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.9% · 58th percentile
Show 74 more
  1. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  2. 2026-10-14 20:33 UTCVendor advisory
  3. 2026-10-14 20:33 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  4. 2026-10-14 19:38 UTCEG score recompute
  5. 2026-10-14 19:38 UTCVendor advisory
  6. 2026-10-14 19:38 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  7. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  8. 2026-10-14 04:28 UTCVendor advisory
  9. 2026-10-14 04:28 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  10. 2026-10-14 03:36 UTCEG score recompute
  11. 2026-10-14 03:36 UTCVendor advisory
  12. 2026-10-14 03:36 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  13. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  14. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  15. 2026-10-12 16:10 UTCEG score recompute
  16. 2026-10-11 19:53 UTCEG score recompute
  17. 2026-10-11 17:06 UTCEG score recompute
  18. 2026-10-11 14:33 UTCEG score recompute
  19. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  20. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  21. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  22. 2026-10-09 00:21 UTCVendor advisory
  23. 2026-10-09 00:21 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  24. 2026-10-08 23:24 UTCEG score recompute
  25. 2026-10-08 23:24 UTCVendor advisory
  26. 2026-10-08 23:23 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  27. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  28. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  29. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  30. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  31. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  32. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  33. 2026-10-02 03:30 UTCVendor advisory
  34. 2026-10-02 03:30 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  35. 2026-10-02 02:42 UTCEG score recompute
  36. 2026-10-02 02:42 UTCVendor advisory
  37. 2026-10-02 02:42 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  38. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  39. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  40. 2026-09-29 01:20 UTCVendor advisory
  41. 2026-09-29 01:20 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  42. 2026-09-29 00:56 UTCEG score recompute
  43. 2026-09-29 00:56 UTCVendor advisory
  44. 2026-09-29 00:56 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  45. 2026-09-28 15:34 UTCVendor advisory
  46. 2026-09-28 15:34 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  47. 2026-09-28 14:28 UTCEG score recompute
  48. 2026-09-28 14:28 UTCVendor advisory
  49. 2026-09-28 14:28 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  50. 2026-09-28 02:19 UTCVendor advisory
  51. 2026-09-28 02:19 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  52. 2026-09-28 02:12 UTCEG score recompute
  53. 2026-09-28 02:12 UTCVendor advisory
  54. 2026-09-28 02:12 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  55. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  56. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  57. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  58. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  59. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  60. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  61. 2026-09-17 19:29 UTCVendor advisory
  62. 2026-09-17 19:29 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  63. 2026-09-17 19:11 UTCVendor advisory
  64. 2026-09-17 19:11 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  65. 2026-09-17 09:32 UTCVendor advisory
  66. 2026-09-17 09:32 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  67. 2026-09-17 08:35 UTCEG score recompute
  68. 2026-09-17 08:35 UTCVendor advisory
  69. 2026-09-17 08:35 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5
  70. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  71. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  72. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  73. 2026-09-14 13:39 UTCVendor advisory
  74. 2026-09-14 13:39 UTCGHSA enrichmentGHSA-6rgh-57xm-37v8 · GitHub CVSS 6.5

Frequently asked(5)

What is CVE-2026-3833?
CVE-2026-3833 is a high-severity vulnerability; its CVE record was 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 made public?
CVE-2026-3833 was made public on April 30, 2026: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on April 30, 2026. EchelonGraph's copy of the record carries a last-modified date of October 26, 2026; the record at its source may have been updated since.
Is CVE-2026-3833 actively exploited?
CVE-2026-3833 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (46th 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.

Dependency Blast Radius

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