CVE-2026-0719: Libsoup: signed to unsigned conversion error leading to stack-based buffer overflow in libsoup ntlm authentication

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-08 · updated 2026-10-26
Weakness: CWE-121

Description

A flaw was identified in the NTLM authentication handling of the libsoup HTTP library, used by GNOME and other applications for network communication. When processing extremely long passwords, an internal size calculation can overflow due to improper use of signed integers. This results in incorrect memory allocation on the stack, followed by unsafe memory copying. As a result, applications using libsoup may crash unexpectedly, creating a denial-of-service risk.

Affected products

Red Hat Enterprise Linux 10: all versions — fixed in 0:3.6.5-3.el10_1.9
Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:3.6.5-3.el10_0.14
Red Hat Enterprise Linux 7 Extended Lifecycle Support: all versions — fixed in 0:2.62.2-11.el7_9
Red Hat Enterprise Linux 8: all versions — fixed in 0:2.62.3-13.el8_10, 0:8.10-7
Red Hat Enterprise Linux 8.2 Advanced Update Support: all versions — fixed in 0:2.62.3-1.el8_2.8, 0:8.10-7.el8_2.1
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: all versions — fixed in 0:2.62.3-2.el8_4.8, 0:8.10-7.el8_4.1
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: all versions — fixed in 0:2.62.3-2.el8_4.8, 0:8.10-7.el8_4.1
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 0:2.62.3-2.el8_6.8, 0:8.10-7.el8_6.1
Red Hat Enterprise Linux 8.6 Telecommunications Update Service: all versions — fixed in 0:2.62.3-2.el8_6.8, 0:8.10-7.el8_6.1
Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions: all versions — fixed in 0:2.62.3-2.el8_6.8, 0:8.10-7.el8_6.1
Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 0:2.62.3-3.el8_8.8, 0:8.10-7.el8_8.1
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 0:2.62.3-3.el8_8.8, 0:8.10-7.el8_8.1
Red Hat Enterprise Linux 9: all versions — fixed in 0:2.72.0-12.el9_7.5
Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions: all versions — fixed in 0:2.72.0-8.el9_0.9
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:2.72.0-8.el9_2.10
Red Hat Enterprise Linux 9.4 Extended Update Support: all versions — fixed in 0:2.72.0-8.el9_4.9
Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:2.72.0-10.el9_6.6
Red Hat OpenShift Dev Spaces (RHOSDS) 3.26: all versions — fixed in sha256:48d31aa446fe1033ad770ed74442053bcee5102035a9c618fb81cde1743a9692, sha256:619c10386e0224e5228876a434c5b8d78d251bc383e2a9491503d6ceddd33c96, sha256:bb9f0ee4fa785a4c3d4a3f6f5e177f4a41350ccef40bc53bfeedee2d52061472

How to fix

Upgrade to a fixed version: Red Hat Enterprise Linux 10 0:3.6.5-3.el10_1.9; Red Hat Enterprise Linux 10.0 Extended Update Support 0:3.6.5-3.el10_0.14; Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:2.62.2-11.el7_9; Red Hat Enterprise Linux 8 0:2.62.3-13.el8_10, 0:8.10-7; Red Hat Enterprise Linux 8.2 Advanced Update Support 0:2.62.3-1.el8_2.8, 0:8.10-7.el8_2.1; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:2.62.3-2.el8_4.8, 0:8.10-7.el8_4.1; Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 0:2.62.3-2.el8_4.8, 0:8.10-7.el8_4.1; Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:2.62.3-2.el8_6.8, 0:8.10-7.el8_6.1; Red Hat Enterprise Linux 8.6 Telecommunications Update Service 0:2.62.3-2.el8_6.8, 0:8.10-7.el8_6.1; Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions 0:2.62.3-2.el8_6.8, 0:8.10-7.el8_6.1; Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:2.62.3-3.el8_8.8, 0:8.10-7.el8_8.1; Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:2.62.3-3.el8_8.8, 0:8.10-7.el8_8.1. Check the vendor advisory for mitigations.

References

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