Vulnerability-Lookup

alsa-2026:38487

Vulnerability from osv_almalinux

Published

2026-07-13 00:00

Modified

2026-07-13 08:56

Summary

Important: xorg-x11-server security update

Details

X.Org is an open-source implementation of the X Window System. It provides the basic low-level functionality that full-fledged graphical user interfaces are designed upon.

Security Fix(es):

xorg: X11: xserver: X.org: glamor Font Atlas Heap Buffer Overflow (CVE-2026-55999)

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.

References

URL

Type

	https://access.redhat.com/errata/RHSA-2026:38487	ADVISORY
	https://access.redhat.com/security/cve/CVE-2026-55999	REPORT
	https://bugzilla.redhat.com/2496165	REPORT
	https://errata.almalinux.org/8/ALSA-2026-38487.html	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "xorg-x11-server-Xdmx"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.11-28.el8_10.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "xorg-x11-server-Xephyr"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.11-28.el8_10.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "xorg-x11-server-Xnest"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.11-28.el8_10.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "xorg-x11-server-Xorg"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.11-28.el8_10.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "xorg-x11-server-Xvfb"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.11-28.el8_10.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "xorg-x11-server-common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.11-28.el8_10.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "xorg-x11-server-devel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.11-28.el8_10.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "xorg-x11-server-source"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.11-28.el8_10.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "X.Org is an open-source implementation of the X Window System. It provides the basic low-level functionality that full-fledged graphical user interfaces are designed upon.  \n\nSecurity Fix(es):  \n\n  * xorg: X11: xserver: X.org: glamor Font Atlas Heap Buffer Overflow (CVE-2026-55999)\n\n\nFor 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.\n",
  "id": "ALSA-2026:38487",
  "modified": "2026-07-13T08:56:34Z",
  "published": "2026-07-13T00:00:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:38487"
    },
    {
      "type": "REPORT",
      "url": "https://access.redhat.com/security/cve/CVE-2026-55999"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/2496165"
    },
    {
      "type": "ADVISORY",
      "url": "https://errata.almalinux.org/8/ALSA-2026-38487.html"
    }
  ],
  "related": [
    "CVE-2026-55999"
  ],
  "summary": "Important: xorg-x11-server security update"
}

CVE-2026-55999 (GCVE-0-2026-55999)

Vulnerability from cvelistv5 – Published: 2026-07-08 08:07 – Updated: 2026-07-09 03:55

Title

xorg-server / xwayland glamor font atlas Heap Buffer Overflow

Summary

Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks.

Severity

8.5 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-122 - Heap-based buffer overflow

Assigner

suse

References

2 references

URL	Tags
https://gitlab.freedesktop.org/xorg/xserver/-/com…	patch
https://www.openwall.com/lists/oss-security/2026/…	vendor-advisory

Impacted products

2 products

Vendor	Product	Version
X.Org	xorg-server	Affected: 0 , < 21.1.24 (rpm)
X.Org	xwayland	Affected: 0 , < 24.1.13 (rpm)

Date Public

2026-07-08 07:51

Credits

Anonymous working with Trend Micro Zero Day Initiative.

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55999",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-08T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-09T03:55:43.683Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageName": "xorg-server",
          "product": "xorg-server",
          "repo": "https://gitlab.freedesktop.org/xorg/xserver/",
          "vendor": "X.Org",
          "versions": [
            {
              "lessThan": "21.1.24",
              "status": "affected",
              "version": "0",
              "versionType": "rpm"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "packageName": "xwayland",
          "product": "xwayland",
          "repo": "https://gitlab.freedesktop.org/xorg/xserver/",
          "vendor": "X.Org",
          "versions": [
            {
              "lessThan": "24.1.13",
              "status": "affected",
              "version": "0",
              "versionType": "rpm"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Anonymous working with Trend Micro Zero Day Initiative."
        }
      ],
      "datePublic": "2026-07-08T07:51:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Local attackers with a X connection able to provide PCX fonts to the X \nserver xorg-server before 21.2.24 and xwayland before 24.1.13 could \ncause a heap buffer overflow via SetFont due to missing glyph boundary checks."
            }
          ],
          "value": "Local attackers with a X connection able to provide PCX fonts to the X \nserver xorg-server before 21.2.24 and xwayland before 24.1.13 could \ncause a heap buffer overflow via SetFont due to missing glyph boundary checks."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-234",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-234 Hijacking a privileged process"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-122",
              "description": "CWE-122 Heap-based buffer overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-08T08:12:17.088Z",
        "orgId": "404e59f5-483d-4b8a-8e7a-e67604dd8afb",
        "shortName": "suse"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://gitlab.freedesktop.org/xorg/xserver/-/commit/fbf7bac22e2c6bd627fb042742a23318263edae1"
        },
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.openwall.com/lists/oss-security/2026/07/08/2"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "xorg-server / xwayland glamor font atlas Heap Buffer Overflow",
      "x_generator": {
        "engine": "Vulnogram 1.0.2"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "404e59f5-483d-4b8a-8e7a-e67604dd8afb",
    "assignerShortName": "suse",
    "cveId": "CVE-2026-55999",
    "datePublished": "2026-07-08T08:07:11.088Z",
    "dateReserved": "2026-06-18T09:26:55.988Z",
    "dateUpdated": "2026-07-09T03:55:43.683Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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.

Action not permitted

alsa-2026:38487

Vulnerability from osv_almalinux

CVE-2026-55999 (GCVE-0-2026-55999)

Tags

Sightings

Nomenclature