VulnSocial

CVE-2026-56000Patch(x.org / x_server)

LOWCVSS 7.8 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch x.org x_server systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

Local attackers with a X connection able to provide GLX commit to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a Heap Use After Free, due to CommonMakeCurrent() pointing into potentially reallocated memory.

x.org CVEsBack to dashboard
0.5/ 10 priority

Sources & remediation

Patch / fix
Weakness type (CWE)
CWE-416

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

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

  • x_server
  • xwayland

Threat summary

  • Patch or workaround signal is available
  • 3 mentions across 3 observed days
  • Momentum state: stable

What's happening

  • Patch or workaround mentioned in 3 signals
  • Technical details provided in 2 signals
  • Peaked 2d ago at 1 mentions (2026-07-14); latest day: 1
  • 3 total mentions across 3 days

Affected systems

Vendors
x.org
Products
x_serverxwayland

Deep dive

Activity timeline3 mentions / 3d
00111Mentions · 2026-07-14: 1Mentions · 2026-07-15: 1Mentions · 2026-07-27: 1Patch / Workaround · 2026-07-14: 1Patch / Workaround · 2026-07-15: 1Patch / Workaround · 2026-07-27: 1Technical Details · 2026-07-14: 1Technical Details · 2026-07-15: 107-1407-1507-27
Signal classification1 categories
Patch
3100.0%
Referenced assets6 URLs
Full discourse3 posts
  • XLibre@XLibreDev
    Patch

    We released the #XLibre Xserver 25.0.0.25, 25.1.9, and beta 25.2.2 during the last 4 days containing #security fixes for #CVE-2026-55999 and CVE-2026-56000. We recommend everyone update ASAP. https://github.com/X11Libre/xserver/releases/tag/xlibre-xserver-25.2.2 https://github.com/X11Libre/xserver/releases/tag/xlibre-xserver-25.1.9 https://github.com/X11Libre/xserver/releases/tag/xlibre-xserver-25.0.0.25

    Post summary

    The text announces new XLibre Xserver releases that fix CVE-2026-55999 and CVE-2026-56000, encouraging users to update without providing any exploit or technical details.

    324014423.2K
    5.3K followersView on X
  • kokumօtօ@__kokumoto
    Patch

    X​.Orgに重大(Critical)な脆弱性。CVE-2026-56000はCVSSv4スコア9.0の解放後メモリ使用。xwaylandのGLX contextTagsにおける不具合。細工されたPCFフォントによるヒープバッファオーバーフローCVE-2026-55999と併せ修正。 https://securityonline.info/xorg-server-cve-2026-56000/

    Post summary

    A critical X.Org vulnerability (CVE-2026-56000) with CVSS 9.0, involving a use‑after‑free in xwayland GLX contextTags, has been patched together with a related heap buffer overflow (CVE-2026-55999), and technical details are provided.

    01062908
    7.7K followersView on X
  • Daily CyberSecurity@Daily_CyberSec
    Patch

    http://X.Org Server ships fixes for two flaws, including CVE-2026-56000, a CVSS 9.0 use-after-free. Update xorg-server and Xwayland now. #XorgServer #Xwayland #UseAfterFree #CVE202656000 #LinuxSecurity #PatchNow #InfoSec http://securityonline.info/xorg-server-cve-2026-56000/

    Post summary

    The post announces that X.Org Server now contains a fix for CVE‑2026‑56000, a high‑severity use‑after‑free flaw, and urges users to update xorg-server and Xwayland immediately.

    00021355
    12.9K followersView on X
CPE platform detail2 entries

2 of 2 entries

PartVendorProductVersionTarget SWTarget HW
Appx.orgx_server---
Appx.orgxwayland---

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