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ZDI publishes five X.Org Server flaws; versions and fixes unstated

1 source · 6 articlesFirst reported Updated ()
What's new

November 10: ZDI’s five X.Org advisories still omit affected versions, fixes, and any exploitation status.

Merged summary · x-ai/grok-4.7 · rewritten as coverage arrivesSummaries by Vani AI

ZDI disclosed five X.Org Server flaws on November 10; versions, fixes, and exploitation status remain unstated.

The Zero Day Initiative published five X.Org Server advisories on November 10, 2026. Two remote code-execution issues require the target to connect to a malicious X11 server: a heap-based buffer overflow in libXrender RenderQueryPictFormats reply handling (ZDI-26-905, CVE-2026-88807) and one in libX11 XkbGetMap reply handling (ZDI-26-906, CVE-2026-88806). ZDI scored both CVSS 8.8. Three local privilege-escalation flaws require existing low-privileged code execution and are scored 7.8: font alias resolution (ZDI-26-903, CVE-2026-50256), an integer overflow in XkbResizeKeySyms (ZDI-26-902, CVE-2026-50258), and a heap overflow in ProcDRI2GetBuffers (ZDI-26-901, CVE-2026-50264). ZDI does not name affected or fixed versions or say whether any flaw is being exploited.

Key facts
  • Two remote flaws, CVE-2026-88807 and CVE-2026-88806, are scored CVSS 8.8.
  • Both remote issues require connecting to a malicious X11 server.
  • Three local flaws are scored CVSS 7.8 and need low-privileged code execution.
  • Local issues: CVE-2026-50256, CVE-2026-50258, and CVE-2026-50264.
  • ZDI states no affected versions, fixes, or exploitation status.
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Timeline

dated events in the reporting · oldest first
  1. Nov 10, 2026ZDI publishes five X.Org Server advisories · ZDI Published Advisories

What each outlet adds

beyond the shared facts
  • ZDI Published AdvisoriesCVSS scores, advisory IDs, and required attacker preconditions for all five
CVEs
CVE-2026-88806CVE-2026-88807CVE-2026-50256CVE-2026-50258CVE-2026-50264CVE-2025-10935
Vendors
X.Org
Products
X.Org ServerlibX11libXrenderlibilbm
Organizations
Zero Day Initiative

Coverage

oldest first · one row per article · UTC
  1. · 5d ago ZDI Published AdvisoriesFirst report

    libilbm ILBM parser heap overflow can execute code via a malicious file

    CVE-2025-10935 requires the user to open a malicious file or page; ZDI scores it 7.8.

  2. · 1d ago ZDI Published Advisories

    X.Org Server font alias overflow allows local privilege escalation

    ZDI rates CVE-2026-50256 at 7.8; attackers must already run low-privileged code.

  3. · 1d ago ZDI Published Advisories

    X.Org Server XkbResizeKeySyms overflow allows local privilege escalation

    ZDI rates CVE-2026-50258 at 7.8 and says low-privileged code is required first.

  4. · 1d ago ZDI Published Advisories

    X.Org libX11 XkbGetMap overflow allows remote code execution

    A victim must connect to a malicious X11 server; ZDI rates CVE-2026-88806 at CVSS 8.8.

  5. · 1d ago ZDI Published Advisories

    X.Org Server ProcDRI2GetBuffers overflow allows local privilege escalation

    ZDI rates CVE-2026-50264 at 7.8; exploitation needs prior low-privileged code execution.

  6. · 1d ago ZDI Published Advisories

    X.Org libXrender reply overflow allows remote code execution

    Exploitation needs a connection to a malicious X11 server; ZDI rates CVE-2026-88807 at CVSS 8.8.

Vulnerabilities in this story

All
CVEVulnerabilityCVSSEPSSSignalsPublished
CVE-2025-10935
———
CVE-2026-50258
+2 related CVEs
CVE-2026-50256CVE-2026-50264
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland
7.8<1%
CVE-2026-88806
Buffer Overflow in libX11 XkbGetMap Leading to Potential Code Execution
7.5—
CVE-2026-88807
Heap Overflow in libXrender via Malicious X Server
8.9—