RHSA-2025:2866 - Security Advisory

Topic

An update for tigervnc is now available for Red Hat Enterprise Linux 8.2 Advanced Update Support.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Virtual Network Computing (VNC) is a remote display system which allows users to view a computing desktop environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. TigerVNC is a suite of VNC servers and clients.

Security Fix(es):

• X.Org: Xwayland: Use-after-free of the root cursor (CVE-2025-26594)
• xorg: xwayland: Use-after-free in SyncInitTrigger() (CVE-2025-26601)
• xorg: xwayland: Use-after-free in PlayReleasedEvents() (CVE-2025-26600)
• xorg: xwayland: Use of uninitialized pointer in compRedirectWindow() (CVE-2025-26599)
• xorg: xwayland: Out-of-bounds write in CreatePointerBarrierClient() (CVE-2025-26598)
• xorg: xwayland: Buffer overflow in XkbChangeTypesOfKey() (CVE-2025-26597)
• xorg: xwayland: Heap overflow in XkbWriteKeySyms() (CVE-2025-26596)
• Xorg: xwayland: Buffer overflow in XkbVModMaskText() (CVE-2025-26595)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server - AUS 8.2 x86_64

Fixes

• BZ - 2345248 - CVE-2025-26594 X.Org: Xwayland: Use-after-free of the root cursor
• BZ - 2345251 - CVE-2025-26601 xorg: xwayland: Use-after-free in SyncInitTrigger()
• BZ - 2345252 - CVE-2025-26600 xorg: xwayland: Use-after-free in PlayReleasedEvents()
• BZ - 2345253 - CVE-2025-26599 xorg: xwayland: Use of uninitialized pointer in compRedirectWindow()
• BZ - 2345254 - CVE-2025-26598 xorg: xwayland: Out-of-bounds write in CreatePointerBarrierClient()
• BZ - 2345255 - CVE-2025-26597 xorg: xwayland: Buffer overflow in XkbChangeTypesOfKey()
• BZ - 2345256 - CVE-2025-26596 xorg: xwayland: Heap overflow in XkbWriteKeySyms()
• BZ - 2345257 - CVE-2025-26595 Xorg: xwayland: Buffer overflow in XkbVModMaskText()

CVEs

• CVE-2025-26594
• CVE-2025-26595
• CVE-2025-26596
• CVE-2025-26597
• CVE-2025-26598
• CVE-2025-26599
• CVE-2025-26600
• CVE-2025-26601

References

• https://access.redhat.com/security/updates/classification/#important