GHSA-G562-3MH5-27V6

Vulnerability from github – Published: 2026-04-23 18:33 – Updated: 2026-06-05 03:31
VLAI
Details

A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of service (DoS) or other severe impacts.

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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  "affected": [],
  "aliases": [
    "CVE-2026-33999"
  ],
  "database_specific": {
    "cwe_ids": [
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    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-23T16:16:24Z",
    "severity": "HIGH"
  },
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  "id": "GHSA-g562-3mh5-27v6",
  "modified": "2026-06-05T03:31:29Z",
  "published": "2026-04-23T18:33:03Z",
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}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.