CVE-2026-88806

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-88806", "assignerOrgId": "404e59f5-483d-4b8a-8e7a-e67604dd8afb", "state": "PUBLISHED", "assignerShortName": "suse", "dateReserved": "2026-09-10T08:35:07.010Z", "datePublished": "2026-09-21T13:42:12.700Z", "dateUpdated": "2026-09-22T03:55:48.003Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "404e59f5-483d-4b8a-8e7a-e67604dd8afb", "shortName": "suse", "dateUpdated": "2026-09-21T13:42:12.700Z"}, "title": "libX11 XkbGetMap Reply Heap-based Buffer Overflow", "datePublic": "2026-09-18T13:33:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-122", "description": "CWE-122 Heap-based buffer overflow", "type": "CWE"}]}], "impacts": [{"capecId": "CAPEC-242", "descriptions": [{"lang": "en", "value": "CAPEC-242 Code Injection"}]}], "affected": [{"vendor": "x.org", "product": "libX11", "packageName": "libX11", "repo": "https://gitlab.freedesktop.org/xorg/lib/libx11", "versions": [{"status": "affected", "version": "0", "lessThan": "1.8.14", "versionType": "semver"}], "defaultStatus": "unaffected"}], "cpeApplicability": [{"operator": "OR", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:x.org:libx11:*:*:*:*:*:*:*:*", "versionStartIncluding": "0", "versionEndExcluding": "1.8.14"}]}]}], "descriptions": [{"lang": "en", "value": "A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<div>A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.</div>"}]}], "references": [{"url": "https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/309", "tags": ["patch"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseSeverity": "HIGH", "baseScore": 7.5, "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"}}], "credits": [{"lang": "en", "value": "Adam Bedard working with TrendAI Zero Day Initiative", "type": "finder"}, {"lang": "en", "value": "Claude:claude-opus-4-6", "type": "tool"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "Vulnogram 1.0.5"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-21T00:00:00+00:00", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3", "id": "CVE-2026-88806"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-22T03:55:48.003Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-88806", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-09-21T14:26:58.764233Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-21T14:39:41.457Z"}}], "cna": {"title": "libX11 XkbGetMap Reply Heap-based Buffer Overflow", "source": {"discovery": "EXTERNAL"}, "credits": [{"lang": "en", "type": "finder", "value": "Adam Bedard working with TrendAI Zero Day Initiative"}, {"lang": "en", "type": "tool", "value": "Claude:claude-opus-4-6"}], "impacts": [{"capecId": "CAPEC-242", "descriptions": [{"lang": "en", "value": "CAPEC-242 Code Injection"}]}], "metrics": [{"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"repo": "https://gitlab.freedesktop.org/xorg/lib/libx11", "vendor": "x.org", "product": "libX11", "versions": [{"status": "affected", "version": "0", "lessThan": "1.8.14", "versionType": "semver"}], "packageName": "libX11", "defaultStatus": "unaffected"}], "datePublic": "2026-09-18T13:33:00.000Z", "references": [{"url": "https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/309", "tags": ["patch"]}], "x_generator": {"engine": "Vulnogram 1.0.5"}, "descriptions": [{"lang": "en", "value": "A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.", "supportingMedia": [{"type": "text/html", "value": "<div>A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.</div>", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-122", "description": "CWE-122 Heap-based buffer overflow"}]}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:x.org:libx11:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "1.8.14", "versionStartIncluding": "0"}], "operator": "OR"}], "operator": "OR"}], "providerMetadata": {"orgId": "404e59f5-483d-4b8a-8e7a-e67604dd8afb", "shortName": "suse", "dateUpdated": "2026-09-21T13:42:12.700Z"}}}, "cveMetadata": {"cveId": "CVE-2026-88806", "state": "PUBLISHED", "dateUpdated": "2026-09-22T03:55:48.003Z", "dateReserved": "2026-09-10T08:35:07.010Z", "assignerOrgId": "404e59f5-483d-4b8a-8e7a-e67604dd8afb", "datePublished": "2026-09-21T13:42:12.700Z", "assignerShortName": "suse"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageName": "libX11", "product": "libX11", "repo": "https://gitlab.freedesktop.org/xorg/lib/libx11", "vendor": "x.org", "versions": [{"lessThan": "1.8.14", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "meissner@suse.de"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map."}], "id": "CVE-2026-88806", "lastModified": "2026-09-22T19:40:05.870", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 5.9, "source": "meissner@suse.de", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-88806", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-09-21T00:00:00+00:00", "version": "2.0.3"}}]}, "published": "2026-09-21T14:17:22.273", "references": [{"source": "meissner@suse.de", "url": "https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/309"}], "sourceIdentifier": "meissner@suse.de", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-122"}], "source": "meissner@suse.de", "type": "Secondary"}]}

{"bugzilla": {"description": "libX11: libX11: Heap-based buffer overflow via malicious X server", "id": "2538514", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2538514"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-787", "details": ["A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.", "A flaw was found in libX11. A heap-based buffer overflow vulnerability exists during the handling of XkbGetMap replies. A remote attacker, by operating a malicious X server, could exploit this flaw to potentially execute arbitrary code or cause a denial of service on the client system. User interaction is required for exploitation."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, users should avoid connecting to untrusted X servers. When using SSH, ensure that X11 forwarding (`ssh -X` or `ssh -Y`) is only enabled for trusted remote hosts. To prevent X11 forwarding for specific hosts, add `ForwardX11 no` to the relevant host entry in `~/.ssh/config` or `/etc/ssh/ssh_config`. Alternatively, disable X11 forwarding globally by setting `ForwardX11 no` in `/etc/ssh/ssh_config`."}, "name": "CVE-2026-88806", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "libX11", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "libX11", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "libX11", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "libX11", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "libX11", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "libX11", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-09-21T13:42:12Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-88806\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-88806\nhttps://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/309"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.8.14)"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "libX11", "source": "cna", "vendor": "x.org"}, "product": "libx11", "vendor": "x.org"}], "created": "2026-09-21T15:30:16.426518+00:00", "updated": "2026-09-23T17:00:08.052021+00:00", "vendors": ["x.org", "x.org$PRODUCT$libx11"]}