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Vulnerabilities

Vulnerability · CVE-2026-33846

Gnutls: gnutls: denial of service via heap buffer overflow in dtls handshake fragment reassembly

Published May 4, 2026 · catalog updated Oct 14, 2026 · Red Hat Red Hat Enterprise Linux 10

Check if you run it

No confirmed exploitation is on record for CVE-2026-33846. EPSS is 1.12%. Act only if a listed version of Red Hat Red Hat Enterprise Linux 10 is installed.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
1.12%
Remediation
Not established
Affected products
vendor Red Hat Red Hat Enterprise Linux 10 · vendor Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support · vendor Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support · vendor Red Hat Red Hat Enterprise Linux 8 · vendor Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support · vendor Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

A heap buffer overflow vulnerability exists in the DTLS handshake fragment reassembly logic of GnuTLS. The issue arises in merge_handshake_packet() where incoming handshake fragments are matched and merged based solely on handshake type, without validating that the message_length field remains consistent across all fragments of the same logical message. An attacker can exploit this by sending crafted DTLS fragments with conflicting message_length values, causing the implementation to allocate a buffer based on a smaller initial fragment and subsequently write beyond its bounds using larger, inconsistent fragments. Because the merge operation does not enforce proper bounds checking against the allocated buffer size, this results in an out-of-bounds write on the heap. The vulnerability is remotely exploitable without authentication via the DTLS handshake path and can lead to application crashes or potential memory corruption.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Red Hat Red Hat Enterprise Linux 10version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 10.0 Extended Update Supportversion unspecified
  • vendor Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Supportversion unspecified
  • vendor Red Hat Red Hat Enterprise Linux 8version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Supportversion unspecified
  • vendor Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-Onversion unspecified

How to fix CVE-2026-33846

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-33846. EPSS is 1.12%. Act only if a listed version of Red Hat Red Hat Enterprise Linux 10 is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-130. EPSS 1.12%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 4, 2026 · Catalog

    Detected

    A heap buffer overflow vulnerability exists in the DTLS handshake fragment reassembly logic of GnuTLS. The issue arises in merge_handshake_packet() where incoming handshake fragments are matched and merged based solely on handshake type, without validating that the message_length field remains consistent across all fragments of the same logical message. An attacker can exploit this by sending craf

  2. Oct 14, 2026 · Catalog

    Updated

    A heap buffer overflow vulnerability exists in the DTLS handshake fragment reassembly logic of GnuTLS. The issue arises in merge_handshake_packet() where incoming handshake fragments are matched and merged based solely on handshake type, without validating that the message_length field remains consistent across all fragments of the same logical message. An attacker can exploit this by sending craf

  3. Oct 14, 2026 · NIST NVD

    Updated

    A heap buffer overflow vulnerability exists in the DTLS handshake fragment reassembly logic of GnuTLS. The issue arises in merge_handshake_packet() where incoming handshake fragments are matched and merged based solely on handshake type, without validating that the message_length field remains consistent across all fragments of the same logical message. An attacker can exploit this by sending craf

Sources

  • CIRCL Vulnerability LookupVulnerability recordCVE-2026-33846

    A heap buffer overflow vulnerability exists in the DTLS handshake fragment reassembly logic of GnuTLS. The issue arises in merge_handshake_packet() where incoming handshake fragments are matched and merged based solely on handshake type, without validating that the message_length

    vulnerability.circl.lu
  • CVE.orgVulnerability recordCVE-2026-33846

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-33846

    30-day exploitation probability 1.1%

    first.org
  • NIST NVDVulnerability recordCVE-2026-33846

    A heap buffer overflow vulnerability exists in the DTLS handshake fragment reassembly logic of GnuTLS. The issue arises in merge_handshake_packet() where incoming handshake fragments are matched and merged based solely on handshake type, without validating that the message_length

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.