{"api_version":"1","generated_at":"2026-08-19T11:44:41+00:00","cve":"CVE-2026-49423","urls":{"html":"https://cve.report/CVE-2026-49423","api":"https://cve.report/api/cve/CVE-2026-49423.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-49423","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-49423"},"summary":{"title":"Remote DOS via uninitialized memory access in KTLS receive","description":"When building the iovec array for a received TLS 1.2 CBC record, ktls_ocf_tls_cbc_decrypt() incremented the iovec index for every mbuf in the chain, including mbufs that were skipped because they contained only TLS header bytes.  This left uninitialized entries in the iovec array.  The iovec array was allocated without zeroing.\n\nA remote TLS peer can cause the kernel to read from uninitialized iovec entries during HMAC computation, resulting in a kernel panic.  The peer must be able to control TCP segmentation such that the first mbuf of a CBC record contains only the 5-byte TLS record header.","state":"PUBLISHED","assigner":"freebsd","published_at":"2026-08-19 07:16:28","updated_at":"2026-08-19 07:16:28"},"problem_types":["CWE-908","CWE-908 CWE-908: Use of Uninitialized Resource"],"metrics":[],"references":[{"url":"https://security.freebsd.org/advisories/FreeBSD-SA-26:46.ktls.asc","name":"https://security.freebsd.org/advisories/FreeBSD-SA-26:46.ktls.asc","refsource":"secteam@freebsd.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-49423","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49423","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"FreeBSD","product":"FreeBSD","version":"affected 15.1-RELEASE p1 release","platforms":[]},{"source":"CNA","vendor":"FreeBSD","product":"FreeBSD","version":"affected 15.0-RELEASE p11 release","platforms":[]},{"source":"CNA","vendor":"FreeBSD","product":"FreeBSD","version":"affected 14.4-RELEASE p7 release","platforms":[]},{"source":"CNA","vendor":"FreeBSD","product":"FreeBSD","version":"affected 14.3-RELEASE p16 release","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Yuxiang Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.1 from Z.ai","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unknown","modules":["ktls"],"product":"FreeBSD","vendor":"FreeBSD","versions":[{"lessThan":"p1","status":"affected","version":"15.1-RELEASE","versionType":"release"},{"lessThan":"p11","status":"affected","version":"15.0-RELEASE","versionType":"release"},{"lessThan":"p7","status":"affected","version":"14.4-RELEASE","versionType":"release"},{"lessThan":"p16","status":"affected","version":"14.3-RELEASE","versionType":"release"}]}],"credits":[{"lang":"en","type":"finder","value":"Yuxiang Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.1 from Z.ai"}],"datePublic":"2026-06-30T20:00:00.000Z","descriptions":[{"lang":"en","value":"When building the iovec array for a received TLS 1.2 CBC record, ktls_ocf_tls_cbc_decrypt() incremented the iovec index for every mbuf in the chain, including mbufs that were skipped because they contained only TLS header bytes.  This left uninitialized entries in the iovec array.  The iovec array was allocated without zeroing.\n\nA remote TLS peer can cause the kernel to read from uninitialized iovec entries during HMAC computation, resulting in a kernel panic.  The peer must be able to control TCP segmentation such that the first mbuf of a CBC record contains only the 5-byte TLS record header."}],"problemTypes":[{"descriptions":[{"cweId":"CWE-908","description":"CWE-908: Use of Uninitialized Resource","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-19T07:01:49.801Z","orgId":"63664ac6-956c-4cba-a5d0-f46076e16109","shortName":"freebsd"},"references":[{"tags":["vendor-advisory"],"url":"https://security.freebsd.org/advisories/FreeBSD-SA-26:46.ktls.asc"}],"title":"Remote DOS via uninitialized memory access in KTLS receive","x_generator":{"engine":"cvelib 1.8.0"}}},"cveMetadata":{"assignerOrgId":"63664ac6-956c-4cba-a5d0-f46076e16109","assignerShortName":"freebsd","cveId":"CVE-2026-49423","datePublished":"2026-08-19T07:01:49.801Z","dateReserved":"2026-05-29T20:24:28.616Z","dateUpdated":"2026-08-19T07:01:49.801Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-19 07:16:28","lastModifiedDate":"2026-08-19 07:16:28","problem_types":["CWE-908","CWE-908 CWE-908: Use of Uninitialized Resource"],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"49423","Ordinal":"1","Title":"Remote DOS via uninitialized memory access in KTLS receive","CVE":"CVE-2026-49423","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"49423","Ordinal":"1","NoteData":"When building the iovec array for a received TLS 1.2 CBC record, ktls_ocf_tls_cbc_decrypt() incremented the iovec index for every mbuf in the chain, including mbufs that were skipped because they contained only TLS header bytes.  This left uninitialized entries in the iovec array.  The iovec array was allocated without zeroing.\n\nA remote TLS peer can cause the kernel to read from uninitialized iovec entries during HMAC computation, resulting in a kernel panic.  The peer must be able to control TCP segmentation such that the first mbuf of a CBC record contains only the 5-byte TLS record header.","Type":"Description","Title":"Remote DOS via uninitialized memory access in KTLS receive"}]}}}