CVE-2020-24659

An issue was discovered in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application's error handling path, where the gnutls_deinit function is called after detecting a handshake failure.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

3.8% chance of exploitation in the next 30 days; higher than 90% of CVEs (scores of 2026-10-25)

CWEs

CWE-476, CWE-787

Published

2020-09-04

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• canonical:ubuntu_linux
• fedoraproject:fedora
• gnu:gnutls
• opensuse:leap

References

• http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00054.html
• http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00060.html
• https://gitlab.com/gnutls/gnutls/-/issues/1071
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/62BUAI4FQQLG6VTKRT7SUZPGJJ4NASQ3/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AWN56FDLQQXT2D2YHNI4TYH432TDMQ7N/

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