CVE-2026-75900

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-75900", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-08-18T14:30:48.257Z", "datePublished": "2026-08-19T07:44:35.968Z", "dateUpdated": "2026-11-06T00:43:52.168Z"}, "containers": {"cna": {"title": "Swtpm: swtpm: out-of-bounds read in swtpm_nvram_checkheader due to sizeof(pointer) vs sizeof(struct) mismatch", "metrics": [{"other": {"content": {"value": "Moderate", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "swtpm", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:enterprise_linux:10"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "virt:rhel/swtpm", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:enterprise_linux:8"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "swtpm", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:enterprise_linux:9"]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-75900", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2517910", "name": "RHBZ#2517910", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "datePublic": "2026-08-19T07:30:46.262Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-125", "description": "Out-of-bounds Read", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-125: Out-of-bounds Read", "workarounds": [{"lang": "en", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.\nFixed version: 0.10.2"}], "timeline": [{"lang": "en", "time": "2026-08-14T00:00:00.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-08-19T07:30:46.262Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "Red Hat would like to thank Suraj Theekshana (\u682a\u5f0f\u4f1a\u793eCyberCrew) for reporting this issue."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-11-06T00:43:52.168Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-21T19:22:31.516001Z", "id": "CVE-2026-75900", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-21T19:22:41.001Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-75900", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-21T19:22:31.516001Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-21T19:22:36.982Z"}}], "cna": {"title": "Swtpm: swtpm: out-of-bounds read in swtpm_nvram_checkheader due to sizeof(pointer) vs sizeof(struct) mismatch", "credits": [{"lang": "en", "value": "Red Hat would like to thank Suraj Theekshana (\u682a\u5f0f\u4f1a\u793eCyberCrew) for reporting this issue."}], "metrics": [{"other": {"type": "Red Hat severity rating", "content": {"value": "Moderate", "namespace": "https://access.redhat.com/security/updates/classification/"}}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.1, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "LOW"}}], "affected": [{"cpes": ["cpe:/a:redhat:enterprise_linux:10"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "packageName": "swtpm", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:enterprise_linux:8"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "packageName": "virt:rhel/swtpm", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:enterprise_linux:9"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "packageName": "swtpm", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}], "timeline": [{"lang": "en", "time": "2026-08-14T00:00:00.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-08-19T07:30:46.262Z", "value": "Made public."}], "datePublic": "2026-08-19T07:30:46.262Z", "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-75900", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2517910", "name": "RHBZ#2517910", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "workarounds": [{"lang": "en", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.\nFixed version: 0.10.2"}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-125", "description": "Out-of-bounds Read"}]}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-11-06T00:43:52.168Z"}, "x_redhatCweChain": "CWE-125: Out-of-bounds Read"}}, "cveMetadata": {"cveId": "CVE-2026-75900", "state": "PUBLISHED", "dateUpdated": "2026-11-06T00:43:52.168Z", "dateReserved": "2026-08-18T14:30:48.257Z", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "datePublished": "2026-08-19T07:44:35.968Z", "assignerShortName": "redhat"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:10"], "defaultStatus": "affected", "packageName": "swtpm", "product": "Red Hat Enterprise Linux 10", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:8"], "defaultStatus": "affected", "packageName": "virt:rhel/swtpm", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:9"], "defaultStatus": "affected", "packageName": "swtpm", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat"}], "source": "secalert@redhat.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log."}, {"lang": "es", "value": "Una vulnerabilidad de lectura fuera de l\u00edmites se encontr\u00f3 en la funci\u00f3n SWTPM_NVRAM_CheckHeader() de swtpm. El guardia de entrada comprueba la longitud del b\u00fafer contra sizeof(bh), donde bh es un puntero, en lugar de sizeof(bh), el tama\u00f1o real de la estructura. Esto permite que un b\u00fafer de tama\u00f1o insuficiente pase la validaci\u00f3n, causando una sobrelectura de heap de 2 bytes en sistemas de 64 bits (6 bytes en 32 bits) al acceder al campo totlen. Esto puede causar la terminaci\u00f3n del demonio en algunas plataformas y filtra datos del heap al registro."}], "id": "CVE-2026-75900", "lastModified": "2026-11-09T20:10:00.200", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 4.2, "source": "secalert@redhat.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-75900", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-21T19:22:31.516001Z", "version": "2.0.3"}}]}, "published": "2026-08-19T08:17:14.073", "references": [{"source": "secalert@redhat.com", "url": "https://access.redhat.com/security/cve/CVE-2026-75900"}, {"source": "secalert@redhat.com", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2517910"}], "sourceIdentifier": "secalert@redhat.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}], "source": "secalert@redhat.com", "type": "Secondary"}]}

{"acknowledgement": "Red Hat would like to thank Suraj Theekshana (\u682a\u5f0f\u4f1a\u793eCyberCrew) for reporting this issue.", "bugzilla": {"description": "swtpm: swtpm: Out-of-bounds read in SWTPM_NVRAM_CheckHeader due to sizeof(pointer) vs sizeof(struct) mismatch", "id": "2517910", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2517910"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.1", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H", "status": "draft"}, "cwe": "CWE-125", "details": ["An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.\nFixed version: 0.10.2"}, "name": "CVE-2026-75900", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "swtpm", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "virt:rhel/swtpm", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "swtpm", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-19T07:30:46Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-75900\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-75900"], "statement": "Red Hat rates this issue as Moderate impact. The SWTPM_NVRAM_CheckHeader() function in swtpm uses sizeof(bh) where bh is a pointer, checking buffer length against 8 bytes (on 64-bit) instead of the 10-byte packed blobheader struct. An attacker with access to the control channel can send an 8-byte state blob that passes this guard; the subsequent read of bh->totlen at offset 6 overreads the heap allocation by 2 bytes. The out-of-bounds value is then printed to the swtpm log, leaking a small amount of adjacent heap data. This is distinct from CVE-2022-23645, which added validation on the hdrsize field below this guard but did not fix the entry length check.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": null}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "Red Hat Enterprise Linux 10", "source": "cna", "vendor": "Red Hat"}, "product": "enterprise_linux", "vendor": "redhat"}], "created": "2026-08-19T20:15:03.313384+00:00", "updated": "2026-08-21T21:16:47.264749+00:00", "vendors": ["redhat", "redhat$PRODUCT$enterprise_linux"]}