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🛡️ CVE-2026-33845 on Ubuntu — gnutls28

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

A flaw in GnuTLS DTLS handshake parsing allows malformed fragments with zero length and non-zero offset, leading to an integer underflow during reassembly and resulting in an out-of-bounds read. This issue is remotely exploitable and may cause information disclosure or denial of service.

Distribution advisory

This page covers CVE-2026-33845 as tracked by Ubuntu, for the package gnutls28. The fix is available in version 3.8.12-2ubuntu1.1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity none, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: None.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

UBUNTU-CVE-2026-33845 is classified as CWE-191: Integer Underflow. A subtraction drops below the minimum for the type and wraps, yielding an unexpectedly large value.

Affected software

UBUNTU-CVE-2026-33845 is recorded against 1 package.

  • gnutls28 (fixed in 3.8.12-2ubuntu1.1)

Timeline and source

Published on 30 April 2026 and last revised on 6 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.cve.org (Report)
www.gnutls.org (Report)
ubuntu.com (Advisory)
ubuntu.com (Advisory)

Other advisories for this package

gnutls28 has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-191: Integer Underflow) in other software:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-04-30
Updated 2026-08-20
Modified 2026-07-06
Fix URL N/A

Affected Packages

Software From version Fixed in
gnutls28 3.8.12-2ubuntu1.1

Site Security Check

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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