CVE-2026-5260: Gnutls: gnutls: information disclosure via heap overread in rsa key exchange

Published May 6, 2026
·
Updated

A flaw was found in libgnutls. A remote attacker, by sending an extremely short premaster secret during an RSA key exchange to a server using an RSA key backed by a PKCS#11 token, could trigger a short heap overread. This memory corruption vulnerability could lead to information disclosure.

Other sources

Gnutls: gnutls: information disclosure via heap overread in rsa key exchange

Microsoft

libgnutls: Fix overread in RSA key exchange with PKCS#11 keys For a server using an RSA key backed by a PKCS#11 token, a client sending an extremely short premaster secret during an RSA key exchange could trigger a short heap overread.

Red Hat

Affected Software

2 affected componentsFixes available
Microsoft azl3 gnutls 3.8.3-11<3.8.13-1
3.8.13-1
debian/gnutls28<=3.7.1-5+deb11u5, <=3.7.9-2+deb12u6, <=3.8.9-3+deb13u3
3.7.1-5+deb11u103.7.9-2+deb12u73.8.9-3+deb13u43.8.13-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 3.8.13-1
  2. Upgrade

    Upgrade debian/gnutls28 to a version that resolves this vulnerability.

    Fixed in 3.7.1-5+deb11u10Fixed in 3.7.9-2+deb12u7Fixed in 3.8.9-3+deb13u4Fixed in 3.8.13-1

Event History

May 6, 2026
Data Sourced
via Red Hat·07:51 PM
DescriptionSeverityAffected Software
May 26, 2026
CVE Published
via MITRE·09:29 PM
Data Sourced
via MITRE·09:29 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·10:16 PM
DescriptionSeverityWeakness
May 31, 2026
Data Sourced
via Microsoft·08:02 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·08:02 AM
Affected Software
Updated
via Microsoft·08:02 AM
DescriptionSeverity
Jul 6, 2026
Data Sourced
via Debian·04:34 PM
DescriptionAffected Software
Data Sourced
via Launchpad·04:34 PM
Description
Jul 7, 2026
Data Sourced
via Ubuntu·04:33 PM
RemedyDescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-5260?

The severity of CVE-2026-5260 is high with a score of 8.2.

2

How do I fix CVE-2026-5260?

To fix CVE-2026-5260, update to the latest version of libgnutls that addresses this vulnerability.

3

What type of attack does CVE-2026-5260 facilitate?

CVE-2026-5260 facilitates an information disclosure attack through a heap overread during RSA key exchange.

4

Which software is affected by CVE-2026-5260?

CVE-2026-5260 affects the debian/gnutls28 software package.

5

What could be the outcome of a successful exploit of CVE-2026-5260?

A successful exploit of CVE-2026-5260 could lead to the disclosure of sensitive information from the server.

Contact

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