CVE-2026-3833Disclosure(gnu / enterprise_linux)

MEDIUMCVSS 7.4 · HIGH

Exploitation ongoing with high activity in latest observed window (1 mentions)

Immediate actions

Patch gnu enterprise_linux systems immediately
Assume compromise if assets are exposed

Recommended action window: Immediate (within 24h)

NVD description

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.

gnu CVEs Back to dashboard

5.0/ 10 priority

Sources & remediation

Exploit / PoC references

Vendor / third-party advisories

Other references

Weakness type (CWE)

CWE-178

Priority

MEDIUM

Exploitation

ACTIVE

PoC

YES

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

enterprise_linux
gnutls
hardened_images
openshift_container_platform

Threat summary

Active exploitation appears in 1 classified signals
Patch or workaround signal is available
3 mentions across 3 observed days
Momentum state: stable

What's happening

Active exploitation reported across 1 signal
Patch or workaround mentioned in 1 signal
Technical details provided in 3 signals
Disclosure: 2 classified signals
Peaked 2d ago at 1 mentions (2026-04-30); latest day: 1
3 total mentions across 3 days

Affected systems

Vendors

gnu redhat

Products

enterprise_linuxgnutlshardened_imagesopenshift_container_platform

7 versions affected across 4 products

Deep dive

Activity timeline3 mentions / 3d

Signal classification2 categories

Disclosure

266.7%

Active Exploitation

133.3%

Referenced assets1 URL

By indicator

https://www.cve.org/CVERecord?id=CVE-2026-3833

Classification over time

Date	Total	Labels

2026-04-30	1	Disclosure1
2026-05-27	1	Disclosure1
2026-06-29	1	Active Exploitation1

Full discourse3 posts

إبراهيم بوحيمد | Ibrahim Buhaimed@buhaimedi134d
Disclosure
صدرت اليوم ٨ ثغرات بتصنيف حرج او عالي الخطورة في مكتبة GnuTLS الي شرحتها في التغريده المقتبسه ـ📍 (CVE-2026-42010) تقييم (NVD): 🔴 9.8 (حرجة) تقييم (Red Hat): 🟠 7.1 (عالية) ـ📍 (CVE-2026-33845) تقييم (NVD): 🔴 9.1 (حرجة) تقييم (Red Hat): 🟠 7.5 (عالية) ـ📍 (CVE-2026-42013) تقييم (Red Hat): 🟠 8.2 (عالية) تصنيف (GnuTLS) الرسمي: 🟡 (متوسطة) ـ📍 (CVE-2026-5260) تقييم (Red Hat): 🟠 8.2 (عالية) ـ📍 (CVE-2026-33846) تقييم (Red Hat): 🟠 7.5 (عالية) ـ📍 (CVE-2026-42009) تقييم (Red Hat): 🟠 7.5 (عالية) ـ📍 (CVE-2026-3833) تقييم (NVD): 🟠 7.4 (عالية) تقييم (Red Hat): 🟡 6.5 (متوسطة) ـ📍 (CVE-2026-42011) تقييم (Red Hat / Ubuntu CVSS): 🟠 7.4 (عالية) أولوية (Ubuntu) الفعلية: 🟡 (متوسطة)
Post summary
The text announces eight new high or critical vulnerabilities in GnuTLS, providing CVE numbers and severity scores from NVD and Red Hat, without referencing any PoC, exploit, active use, or patch information.
03023124.3K
50.0K followersView on X
𝔸𝕟𝕠𝕟𝕪𝕞𝕠𝕦𝕤 ℍ𝕒𝕔𝕜𝕥𝕚𝕧𝕚𝕤𝕥☭⃠🅇@YourAnon_irc101d
Active Exploitation
Cisco CUCM (CVE-2026-20230) actively exploited for root access, jeopardizing real-time comms. New GnuTLS flaws (CVE-2026-3833, etc.) impact TLS/DTLS integrity. Patch immediately! #Cybersecurity #Vulnerabilities #RealTimeComms
Post summary
Cisco CUCM’s CVE‑2026‑20230 is actively exploited for root access, and new GnuTLS CVEs (e.g., CVE‑2026‑3833) threaten TLS/DTLS integrity; immediate patching is urged.
0000072
14 followersView on X
CVE@CVEnew161d
Disclosure
CVE-2026-3833 A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of `nameConstraints` labels, specifically for `dNSName` (DNS) o… https://www.cve.org/CVERecord?id=CVE-2026-3833
Post summary
A vulnerability in gnutls involving case-sensitve nameConstraints comparisons on dNSName is disclosed, with technical details provided but no PoC, exploit, patch, or active exploitation evidence.
00000107
57.3K followersView on X

CPE platform detail8 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

8 of 8 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	gnu	gnutls	-	-	-
OS	redhat	enterprise_linux	10.0	-	-
OS	redhat	enterprise_linux	6.0	-	-
OS	redhat	enterprise_linux	7.0	-	-
OS	redhat	enterprise_linux	8.0	-	-
OS	redhat	enterprise_linux	9.0	-	-
App	redhat	hardened_images	-	-	-
App	redhat	openshift_container_platform	4.0	-	-

Explore more

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What researchers are saying

CVE-2026-3833

إبراهيم بوحيمد | Ibrahim Buhaimed[verified]@buhaimediDisclosure

The text announces eight new high or critical vulnerabilities in GnuTLS, providing CVE numbers and severity scores from NVD and Red Hat, without referencing any PoC, exploit, active use, or patch information.

𝔸𝕟𝕠𝕟𝕪𝕞𝕠𝕦𝕤 ℍ𝕒𝕔𝕜𝕥𝕚𝕧𝕚𝕤𝕥☭⃠🅇@YourAnon_ircActive Exploitation

Cisco CUCM’s CVE‑2026‑20230 is actively exploited for root access, and new GnuTLS CVEs (e.g., CVE‑2026‑3833) threaten TLS/DTLS integrity; immediate patching is urged.

CVE@CVEnewDisclosure

A vulnerability in gnutls involving case-sensitve nameConstraints comparisons on dNSName is disclosed, with technical details provided but no PoC, exploit, patch, or active exploitation evidence.