VulnSocial

CVE-2026-50257Patch(redhat / enterprise_linux)

LOWCVSS 7.8 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch redhat enterprise_linux systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

A use-after-free flaw was found in the X.Org X server and Xwayland in miSyncDestroyFence(). A client that sets up multiple fence triggers can trigger a use-after-free function pointer call. An attacker would connect to the X server to set up a fence and await that fence, then a second X connection destroys the fence, causing the use-after-free. This may be used to crash the server, or for privilege escalation if the X server runs as root.

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1.0/ 10 priority

Sources & remediation

Patch / fix
Vendor / third-party advisories
Other references
Weakness type (CWE)
CWE-416

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • enterprise_linux
  • x_server
  • xwayland

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • 1 total mentions across 1 day

Affected systems

Vendors
redhatx.org
Products
enterprise_linuxx_serverxwayland

4 versions affected across 3 products

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-06-06: 1Patch / Workaround · 2026-06-06: 106-06
Signal classification1 categories
Patch
1100.0%
Referenced assets2 URLs
Full discourse1 post
  • XLibre@XLibreDev
    Patch

    We released the #XLibre Xserver 25.0.0.24 and 25.1.6 on Jun 05 containing #security fixes for #CVE-2026-50256, CVE-2026-50257, CVE-2026-50258, CVE-2026-50259, CVE-2026-50260, CVE-2026-50261, CVE-2026-50262, and CVE-2026-50263. https://github.com/X11Libre/xserver/releases/tag/xlibre-xserver-25.0.0.24 https://github.com/X11Libre/xserver/releases/tag/xlibre-xserver-25.1.6

    Post summary

    The announcement informs that new XLibre Xserver releases include security patches for a set of CVEs, with links to the corresponding GitHub release notes.

    820215844.8K
    5.3K followersView on X
CPE platform detail6 entries

6 of 6 entries

PartVendorProductVersionTarget SWTarget HW
OSredhatenterprise_linux10.0--
OSredhatenterprise_linux7.0--
OSredhatenterprise_linux8.0--
OSredhatenterprise_linux9.0--
Appx.orgx_server---
Appx.orgxwayland---

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