Libgnutls RSA PKCS#11 Key Exchange Overread Info Disclosure
CVE-2026-5260 Published on May 26, 2026

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

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Vulnerability Analysis

CVE-2026-5260 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
LOW
Integrity Impact:
NONE
Availability Impact:
HIGH

Timeline

Reported to Red Hat.

Made public.

Weakness Type

Buffer Over-read

The software reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer. This typically occurs when the pointer or its index is incremented to a position beyond the bounds of the buffer or when pointer arithmetic results in a position outside of the valid memory location to name a few. This may result in exposure of sensitive information or possibly a crash.


Products Associated with CVE-2026-5260

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-5260 are published in these products:

Canonical Ubuntu Linux
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Hummingbird
 
Red Hat Openshift
 
Red Hat Enterprise Linux Eus
 
Red Hat Rhui
 
Red Hat Discovery
 
Red Hat Rhel Eus
 
Red Hat Rhel Aus
 
Red Hat Rhel Eus Long Life
 
Red Hat Rhel E4s
 
Red Hat Rhel Tus
 

Exploit Probability

EPSS
0.77%
Percentile
50.72%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.