CVE-2025-49179: Xorg-x11-server-xwayland: xorg-x11-server: tigervnc: integer overflow in x record extension

Severity: high (CVSS 7.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-06-17 · updated 2026-06-30
Weakness: CWE-190

Description

A flaw was found in the X Record extension. The RecordSanityCheckRegisterClients function does not check for an integer overflow when computing request length, which allows a client to bypass length checks.

Affected products

Red Hat Enterprise Linux 10: all versions — fixed in 0:24.1.5-4.el10_0
Red Hat Enterprise Linux 6: all versions
Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION: all versions — fixed in 0:1.1.0-25.el6_10.1
Red Hat Enterprise Linux 7.7 Advanced Update Support: all versions — fixed in 0:1.8.0-17.el7_7.1
Red Hat Enterprise Linux 7 Extended Lifecycle Support: all versions — fixed in 0:1.20.4-32.el7_9, 0:1.8.0-36.el7_9.2
Red Hat Enterprise Linux 8: all versions — fixed in 0:1.15.0-7.el8_10, 0:1.20.11-26.el8_10, 0:21.1.3-18.el8_10
Red Hat Enterprise Linux 8.2 Advanced Update Support: all versions — fixed in 0:1.20.6-4.el8_2, 0:1.9.0-15.el8_2.14
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: all versions — fixed in 0:1.11.0-8.el8_4.13, 0:1.20.10-2.el8_4
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: all versions — fixed in 0:1.11.0-8.el8_4.13, 0:1.20.10-2.el8_4
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 0:1.12.0-6.el8_6.14, 0:1.20.11-5.el8_6.3, 0:21.1.3-2.el8_6.4
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: all versions — fixed in 0:1.12.0-6.el8_6.14, 0:21.1.3-2.el8_6.4
Red Hat Enterprise Linux 8.6 Telecommunications Update Service: all versions — fixed in 0:1.12.0-6.el8_6.14, 0:1.20.11-5.el8_6.3, 0:21.1.3-2.el8_6.4
Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions: all versions — fixed in 0:1.12.0-6.el8_6.14, 0:1.20.11-5.el8_6.3, 0:21.1.3-2.el8_6.4
Red Hat Enterprise Linux 8.8 Extended Update Support Long-Life Add-On: all versions — fixed in 0:1.20.11-16.el8_8, 0:21.1.3-11.el8_8
Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 0:1.12.0-15.el8_8.14, 0:1.20.11-16.el8_8, 0:21.1.3-11.el8_8
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 0:1.12.0-15.el8_8.14, 0:1.20.11-16.el8_8, 0:21.1.3-11.el8_8
Red Hat Enterprise Linux 9: all versions — fixed in 0:1.14.1-8.el9_6, 0:1.20.11-31.el9_6, 0:23.2.7-4.el9_6
Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions: all versions — fixed in 0:1.11.0-22.el9_0.15, 0:1.20.11-11.el9_0, 0:21.1.3-3.el9_0
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:1.12.0-14.el9_2.12, 0:1.20.11-18.el9_2, 0:21.1.3-8.el9_2
Red Hat Enterprise Linux 9.4 Extended Update Support: all versions — fixed in 0:1.13.1-8.el9_4.7, 0:1.20.11-26.el9_4, 0:22.1.9-6.el9_4
X.Org xwayland: before 24.1.7 — fixed in 24.1.7

How to fix

Upgrade to a fixed version: Red Hat Enterprise Linux 10 0:24.1.5-4.el10_0; Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION 0:1.1.0-25.el6_10.1; Red Hat Enterprise Linux 7.7 Advanced Update Support 0:1.8.0-17.el7_7.1; Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:1.20.4-32.el7_9, 0:1.8.0-36.el7_9.2; Red Hat Enterprise Linux 8 0:1.15.0-7.el8_10, 0:1.20.11-26.el8_10, 0:21.1.3-18.el8_10; Red Hat Enterprise Linux 8.2 Advanced Update Support 0:1.20.6-4.el8_2, 0:1.9.0-15.el8_2.14; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:1.11.0-8.el8_4.13, 0:1.20.10-2.el8_4; Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 0:1.11.0-8.el8_4.13, 0:1.20.10-2.el8_4; Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:1.12.0-6.el8_6.14, 0:1.20.11-5.el8_6.3, 0:21.1.3-2.el8_6.4; Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:1.12.0-6.el8_6.14, 0:21.1.3-2.el8_6.4; Red Hat Enterprise Linux 8.6 Telecommunications Update Service 0:1.12.0-6.el8_6.14, 0:1.20.11-5.el8_6.3, 0:21.1.3-2.el8_6.4; Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions 0:1.12.0-6.el8_6.14, 0:1.20.11-5.el8_6.3, 0:21.1.3-2.el8_6.4. Check the vendor advisory for mitigations.

References

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