CVE-2026-55999

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

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-55999", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-07-08T12:09:49.057066Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-08T12:10:08.315Z"}}], "cna": {"title": "xorg-server / xwayland glamor font atlas Heap Buffer Overflow", "source": {"discovery": "EXTERNAL"}, "credits": [{"lang": "en", "type": "finder", "value": "Anonymous working with Trend Micro Zero Day Initiative."}], "impacts": [{"capecId": "CAPEC-234", "descriptions": [{"lang": "en", "value": "CAPEC-234 Hijacking a privileged process"}]}], "metrics": [{"format": "CVSS", "cvssV3_1": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"repo": "https://gitlab.freedesktop.org/xorg/xserver/", "vendor": "X.Org", "product": "xorg-server", "versions": [{"status": "affected", "version": "0", "lessThan": "21.1.24", "versionType": "rpm"}], "packageName": "xorg-server", "defaultStatus": "unaffected"}, {"repo": "https://gitlab.freedesktop.org/xorg/xserver/", "vendor": "X.Org", "product": "xwayland", "versions": [{"status": "affected", "version": "0", "lessThan": "24.1.13", "versionType": "rpm"}], "packageName": "xwayland", "defaultStatus": "unaffected"}], "datePublic": "2026-07-08T07:51:00.000Z", "references": [{"url": "https://gitlab.freedesktop.org/xorg/xserver/-/commit/fbf7bac22e2c6bd627fb042742a23318263edae1", "tags": ["patch"]}, {"url": "https://www.openwall.com/lists/oss-security/2026/07/08/2", "tags": ["vendor-advisory"]}], "x_generator": {"engine": "Vulnogram 1.0.2"}, "descriptions": [{"lang": "en", "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.", "supportingMedia": [{"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.", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-122", "description": "CWE-122 Heap-based buffer overflow"}]}], "providerMetadata": {"orgId": "404e59f5-483d-4b8a-8e7a-e67604dd8afb", "shortName": "suse", "dateUpdated": "2026-07-08T08:12:17.088Z"}}}, "cveMetadata": {"cveId": "CVE-2026-55999", "state": "PUBLISHED", "dateUpdated": "2026-07-09T03:55:43.683Z", "dateReserved": "2026-06-18T09:26:55.988Z", "assignerOrgId": "404e59f5-483d-4b8a-8e7a-e67604dd8afb", "datePublished": "2026-07-08T08:07:11.088Z", "assignerShortName": "suse"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"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"}]}], "source": "meissner@suse.de"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:*", "matchCriteriaId": "7952D780-B208-4D17-BD47-59B9C820E66F", "versionEndExcluding": "21.2.24", "vulnerable": true}, {"criteria": "cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:*", "matchCriteriaId": "17B539FB-255A-427D-9DD3-659AC3BEE4D4", "versionEndExcluding": "24.1.13", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "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."}], "id": "CVE-2026-55999", "lastModified": "2026-07-09T19:49:51.483", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 1.8, "impactScore": 6.0, "source": "meissner@suse.de", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55999", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-07-08T00:00:00+00:00", "version": "2.0.3"}}]}, "published": "2026-07-08T09:16:29.800", "references": [{"source": "meissner@suse.de", "tags": ["Patch"], "url": "https://gitlab.freedesktop.org/xorg/xserver/-/commit/fbf7bac22e2c6bd627fb042742a23318263edae1"}, {"source": "meissner@suse.de", "tags": ["Mailing List", "Patch", "Third Party Advisory"], "url": "https://www.openwall.com/lists/oss-security/2026/07/08/2"}], "sourceIdentifier": "meissner@suse.de", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-122"}], "source": "meissner@suse.de", "type": "Secondary"}]}

{"bugzilla": {"description": "xorg: X11: xserver: X.org: glamor Font Atlas Heap Buffer Overflow", "id": "2496165", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2496165"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-805", "details": ["A flaw was found in the glamor_font_get() function of the xorg-x11-server. This vulnerability, a heap buffer overflow, occurs when the server processes a specially crafted PCF font file where individual glyph metrics exceed the declared maximum bounds. An authenticated X client can exploit this by loading a malicious font and drawing text, potentially leading to arbitrary code execution with attacker-controlled content and extent. This affects servers utilizing the glamor acceleration backend, such as Xorg with the modesetting driver and Xwayland."], "name": "CVE-2026-55999", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "xorg-x11-server-Xwayland", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Affected", "package_name": "xorg-x11-server", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "xorg-x11-server", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "xorg-x11-server", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "xorg-x11-server-Xwayland", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "xorg-x11-server", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "xorg-x11-server-Xwayland", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-07-08T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-55999\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-55999"], "statement": "This Important flaw in xorg-x11-server allows an authenticated X client to achieve arbitrary code execution. By processing a malicious PCF font file where glyph metrics exceed declared bounds, a heap buffer overflow occurs within the glamor acceleration backend. This vulnerability primarily impacts Red Hat systems running Xorg with the modesetting driver or Xwayland, typically found in desktop environments.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,21.1.24)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "xorg-server", "source": "cna", "vendor": "X.Org"}, "product": "xorg-server", "vendor": "x.org"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,24.1.13)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "xwayland", "source": "cna", "vendor": "X.Org"}, "product": "xwayland", "vendor": "x.org"}], "created": "2026-07-08T09:30:04.002671+00:00", "updated": "2026-08-01T16:45:03.449019+00:00", "vendors": ["x.org", "x.org$PRODUCT$xorg-server", "x.org$PRODUCT$xwayland"]}