Red Hat Security Advisory: tigervnc security update
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.
AI Analysis
Technical Summary
This security advisory from Red Hat addresses multiple vulnerabilities in TigerVNC and X.Org's Xwayland component, including use-after-free (CVE-2025-26594, CVE-2025-26600, CVE-2025-26601), buffer overflows (CVE-2025-26595, CVE-2025-26597), heap overflow (CVE-2025-26596), out-of-bounds write (CVE-2025-26598), and use of uninitialized pointer (CVE-2025-26599). These issues affect the remote display system TigerVNC and its Xwayland integration, potentially impacting remote desktop functionality. Red Hat has released security updates for Red Hat Enterprise Linux 7 Extended Lifecycle Support to address these vulnerabilities. The advisory references multiple bugzilla entries and provides package updates for various architectures. No CVSS scores are included in the advisory, but the severity is rated as Important.
Potential Impact
The vulnerabilities include memory corruption issues such as use-after-free, buffer overflows, heap overflow, and out-of-bounds writes in the Xwayland component used by TigerVNC. These could potentially lead to crashes or arbitrary code execution if exploited. The advisory does not specify known exploits in the wild. The impact is rated as Important by Red Hat, indicating significant security concerns that warrant prompt attention.
Mitigation Recommendations
Red Hat has released security updates for TigerVNC and related Xwayland components in Red Hat Enterprise Linux 7 Extended Lifecycle Support. Users should apply the provided updates as detailed in the Red Hat advisory RHSA-2025:2861 and the referenced article https://access.redhat.com/articles/11258. No additional mitigation steps are indicated in the advisory. Patch status is confirmed as available via official Red Hat updates.
Red Hat Security Advisory: tigervnc security update
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.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This security advisory from Red Hat addresses multiple vulnerabilities in TigerVNC and X.Org's Xwayland component, including use-after-free (CVE-2025-26594, CVE-2025-26600, CVE-2025-26601), buffer overflows (CVE-2025-26595, CVE-2025-26597), heap overflow (CVE-2025-26596), out-of-bounds write (CVE-2025-26598), and use of uninitialized pointer (CVE-2025-26599). These issues affect the remote display system TigerVNC and its Xwayland integration, potentially impacting remote desktop functionality. Red Hat has released security updates for Red Hat Enterprise Linux 7 Extended Lifecycle Support to address these vulnerabilities. The advisory references multiple bugzilla entries and provides package updates for various architectures. No CVSS scores are included in the advisory, but the severity is rated as Important.
Potential Impact
The vulnerabilities include memory corruption issues such as use-after-free, buffer overflows, heap overflow, and out-of-bounds writes in the Xwayland component used by TigerVNC. These could potentially lead to crashes or arbitrary code execution if exploited. The advisory does not specify known exploits in the wild. The impact is rated as Important by Red Hat, indicating significant security concerns that warrant prompt attention.
Mitigation Recommendations
Red Hat has released security updates for TigerVNC and related Xwayland components in Red Hat Enterprise Linux 7 Extended Lifecycle Support. Users should apply the provided updates as detailed in the Red Hat advisory RHSA-2025:2861 and the referenced article https://access.redhat.com/articles/11258. No additional mitigation steps are indicated in the advisory. Patch status is confirmed as available via official Red Hat updates.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2025:2861
- Cve Count
- 8
- Additional Cves
- ["CVE-2025-26595","CVE-2025-26596","CVE-2025-26597","CVE-2025-26598","CVE-2025-26599","CVE-2025-26600","CVE-2025-26601"]
- Cvss Version
- null
Threat ID: 6a3da1d74853345fc18277d0
Added to database: 06/25/2026, 21:47:03 UTC
Last enriched: 06/25/2026, 22:16:22 UTC
Last updated: 06/29/2026, 03:51:10 UTC
Views: 4
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