{"id":"CVE-2026-43377","state":"PUBLISHED","title":"ksmbd: Don't log keys in SMB3 signing and encryption key generation","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: Don't log keys in SMB3 signing and encryption key generation\n\nWhen KSMBD_DEBUG_AUTH logging is enabled, generate_smb3signingkey() and\ngenerate_smb3encryptionkey() log the session, signing, encryption, and\ndecryption key bytes. Remove the logs to avoid exposing credentials.","publishedAt":"2026-05-08T14:21:26.618Z","updatedAt":"2026-08-05T12:27:36.806Z","severity":{"score":8.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"4084ed720d7d5f4e975c9e4a6267a552dad3b24a","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"fec5c70b82af3f59f15bb984df94e5ad1fccfb1e","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"3fe2d9ec166b7df9a8df6c0fdcfc210572e27e3f","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"407cc37c21d51f9b9d4d20204b04890880cfa6ae","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"c6b01b997a2094969e315f1ebfc1d64b8ae2163d","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"441336115df26b966575de56daf7107ed474faed","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/auth.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.20","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/auth.c"]}],"references":["https://git.kernel.org/stable/c/4084ed720d7d5f4e975c9e4a6267a552dad3b24a","https://git.kernel.org/stable/c/fec5c70b82af3f59f15bb984df94e5ad1fccfb1e","https://git.kernel.org/stable/c/3fe2d9ec166b7df9a8df6c0fdcfc210572e27e3f","https://git.kernel.org/stable/c/407cc37c21d51f9b9d4d20204b04890880cfa6ae","https://git.kernel.org/stable/c/c6b01b997a2094969e315f1ebfc1d64b8ae2163d","https://git.kernel.org/stable/c/441336115df26b966575de56daf7107ed474faed"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43377.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43377","state":"PUBLISHED","datePublished":"2026-05-08T14:21:26.618Z","dateUpdated":"2026-08-05T12:27:36.806Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:56.006Z"},"containers":{"cna":{"title":"ksmbd: Don't log keys in SMB3 signing and encryption key generation","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: Don't log keys in SMB3 signing and encryption key generation\n\nWhen KSMBD_DEBUG_AUTH logging is enabled, generate_smb3signingkey() and\ngenerate_smb3encryptionkey() log the session, signing, encryption, and\ndecryption key bytes. Remove the logs to avoid exposing credentials."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"4084ed720d7d5f4e975c9e4a6267a552dad3b24a","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"fec5c70b82af3f59f15bb984df94e5ad1fccfb1e","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"3fe2d9ec166b7df9a8df6c0fdcfc210572e27e3f","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"407cc37c21d51f9b9d4d20204b04890880cfa6ae","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"c6b01b997a2094969e315f1ebfc1d64b8ae2163d","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"441336115df26b966575de56daf7107ed474faed","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/auth.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.20","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/auth.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4084ed720d7d5f4e975c9e4a6267a552dad3b24a"},{"url":"https://git.kernel.org/stable/c/fec5c70b82af3f59f15bb984df94e5ad1fccfb1e"},{"url":"https://git.kernel.org/stable/c/3fe2d9ec166b7df9a8df6c0fdcfc210572e27e3f"},{"url":"https://git.kernel.org/stable/c/407cc37c21d51f9b9d4d20204b04890880cfa6ae"},{"url":"https://git.kernel.org/stable/c/c6b01b997a2094969e315f1ebfc1d64b8ae2163d"},{"url":"https://git.kernel.org/stable/c/441336115df26b966575de56daf7107ed474faed"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","baseScore":8.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - ksmbd processes SMB2/SMB3 negotiate and session setup over TCP, normally port 445, and the affected key-generation functions are reached from network SMB session setup packets.\nAC:L - In the vulnerable configuration with KSMBD_DEBUG_AUTH enabled, a client can reliably trigger the logging by completing a normal SMB3 authenticated session setup with signing or encryption negotiated; there is no race or probabilistic condition.\nPR:L - The key logging happens after NTLM or Kerberos authentication succeeds, not in the pre-auth negotiate/challenge path, so the attacker needs at least a valid low-privilege SMB account or equivalent authenticated session.\nUI:N - No victim user action is required once the SMB server is running and auth debug logging is enabled; the attacker can initiate the SMB session directly.\nS:U - The exposure is within the same ksmbd/kernel host security scope and does not cross a VM, hypervisor, IOMMU, or sandbox boundary.\nC:H - The vulnerable logs disclose full SMB session, signing, encryption, and decryption keys, which can expose protected SMB session contents and authentication-derived key material.\nI:H - Leaked SMB signing and encryption keys can allow forging or tampering with protected SMB session traffic in a plausible capture/injection scenario, compromising integrity of the session.\nA:N - The bug is an information disclosure through logging of key bytes and does not corrupt memory, crash the kernel, hang the service, or otherwise directly affect availability."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:27:36.806Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.1.167"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.6.130"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.12.78"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.18.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.19.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}