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

Severity: high (CVSS 8.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-26 · updated 2026-10-30
Weakness: CWE-126

Description

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.

Affected products

[UNKNOWN] gnutls: 0
Red Hat Cert Manager support for Red Hat OpenShift release 1.17: all versions — fixed in 1791371080
Red Hat Cert Manager support for Red Hat OpenShift release 1.18: all versions — fixed in 1791459707
Red Hat Cert Manager support for Red Hat OpenShift release 1.20: all versions — fixed in 1790598593
Red Hat OpenShift Container Platform 4.18: all versions — fixed in 418.94.202608142238-0
Red Hat Discovery 2: all versions — fixed in 1782159791
Red Hat Enterprise Linux 10: all versions — fixed in 0:3.8.10-4.el10_2
Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:3.8.9-9.el10_0.19
Red Hat Enterprise Linux 8: all versions — fixed in 0:3.6.16-8.el8_10.6
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: all versions — fixed in 0:3.6.14-10.el8_4.1
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: all versions — fixed in 0:3.6.14-10.el8_4.1
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 0:3.6.16-5.el8_6.5
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: all versions — fixed in 0:3.6.16-5.el8_6.5
Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 0:3.6.16-7.el8_8.4
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 0:3.6.16-7.el8_8.4
Red Hat Enterprise Linux 9: all versions — fixed in 0:3.8.10-4.el9_8
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:3.7.6-21.el9_2.7
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions: all versions — fixed in 0:3.8.3-4.el9_4.6
Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:3.8.3-6.el9_6.4
Red Hat Hardened Images: all versions — fixed in 3.8.13-1.hum1
Red Hat OpenShift AI 3.4: all versions — fixed in 1790703542
Red Hat OpenShift Container Platform 4.12: all versions — fixed in 412.86.202608241157-0
Red Hat OpenShift Container Platform 4.13: all versions — fixed in 413.92.202609302032-0
Red Hat OpenShift Container Platform 4.14: all versions — fixed in 414.92.202609111941-0
Red Hat OpenShift Container Platform 4.15: all versions — fixed in 415.92.202610081130-0
Red Hat OpenShift Container Platform 4.16: all versions — fixed in 416.94.202608150307-0
Red Hat OpenShift Container Platform 4.17: all versions — fixed in 417.94.202608250221-0
Red Hat OpenShift Container Platform 4.19: all versions — fixed in 4.19.9.6.202607151909-0
Red Hat OpenShift Container Platform 4.20: all versions — fixed in 4.20.9.6.202610242033-0
Red Hat OpenShift Container Platform 4.21: all versions — fixed in 4.21.9.6.202610241345-0

How to fix

Upgrade to a fixed version: Red Hat Cert Manager support for Red Hat OpenShift release 1.17 1791371080; Red Hat Cert Manager support for Red Hat OpenShift release 1.18 1791459707; Red Hat Cert Manager support for Red Hat OpenShift release 1.20 1790598593; Red Hat OpenShift Container Platform 4.18 418.94.202608142238-0; Red Hat Discovery 2 1782159791; Red Hat Enterprise Linux 10 0:3.8.10-4.el10_2; Red Hat Enterprise Linux 10.0 Extended Update Support 0:3.8.9-9.el10_0.19; Red Hat Enterprise Linux 8 0:3.6.16-8.el8_10.6; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:3.6.14-10.el8_4.1; Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 0:3.6.14-10.el8_4.1; Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:3.6.16-5.el8_6.5; Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:3.6.16-5.el8_6.5. Check the vendor advisory for mitigations.

References

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