{"api_version":"1","generated_at":"2026-08-22T21:52:58+00:00","cve":"CVE-2026-74659","urls":{"html":"https://cve.report/CVE-2026-74659","api":"https://cve.report/api/cve/CVE-2026-74659.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74659","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74659"},"summary":{"title":"net: bridge: mrp: fix uninitialised bytes on the wire","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: mrp: fix uninitialised bytes on the wire\n\nbr_mrp_alloc_test_skb() builds MRP test frames on an skb from\ndev_alloc_skb(), which does not clear the linear data area.  On the MRA\nring-role branch the sub-option TLV header is appended with\n\n\tsub_tlv = skb_put(skb, sizeof(*sub_tlv));\n\tsub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR;\n\nso sub_tlv->length is never written, and the two trailing alignment bytes\nare appended with a bare skb_put() that does not clear them either.  The\nneighbouring oui and sub_opt regions are explicitly zeroed, so three\nuninitialised bytes are left in every MRA MRP_Test frame that goes out.\n\nPut the sub-option TLV header and the alignment padding in a single\nskb_put_zero(), which clears both.  The AUTO_MGR sub-TLV carries no\npayload, so the zeroed length field is already the value it should have.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-22 16:16:39","updated_at":"2026-08-22 16:16:39"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/63488dba65ef91373ef616575b32eb0eb21459f4","name":"https://git.kernel.org/stable/c/63488dba65ef91373ef616575b32eb0eb21459f4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5912cf1822fbe53ae275c147868740eb384a5d3e","name":"https://git.kernel.org/stable/c/5912cf1822fbe53ae275c147868740eb384a5d3e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/014c062d23c63ec77ef2cf17a0d9363c7441cc94","name":"https://git.kernel.org/stable/c/014c062d23c63ec77ef2cf17a0d9363c7441cc94","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/06d58b8d2f053ced82e01efaeb6e7c82891eed58","name":"https://git.kernel.org/stable/c/06d58b8d2f053ced82e01efaeb6e7c82891eed58","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e08665218040f8e312abe40f74543186f3c2c941","name":"https://git.kernel.org/stable/c/e08665218040f8e312abe40f74543186f3c2c941","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7ebc23ff03668042e0b0e4034bb1518d36198d9e","name":"https://git.kernel.org/stable/c/7ebc23ff03668042e0b0e4034bb1518d36198d9e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a5e385eeb2d6dbbbdebfa050e67c34734ae12693","name":"https://git.kernel.org/stable/c/a5e385eeb2d6dbbbdebfa050e67c34734ae12693","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74659","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74659","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f7458934b0791c39a001e4d902fc3bf697b439b5 014c062d23c63ec77ef2cf17a0d9363c7441cc94 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f7458934b0791c39a001e4d902fc3bf697b439b5 7ebc23ff03668042e0b0e4034bb1518d36198d9e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f7458934b0791c39a001e4d902fc3bf697b439b5 06d58b8d2f053ced82e01efaeb6e7c82891eed58 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f7458934b0791c39a001e4d902fc3bf697b439b5 a5e385eeb2d6dbbbdebfa050e67c34734ae12693 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f7458934b0791c39a001e4d902fc3bf697b439b5 5912cf1822fbe53ae275c147868740eb384a5d3e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f7458934b0791c39a001e4d902fc3bf697b439b5 e08665218040f8e312abe40f74543186f3c2c941 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f7458934b0791c39a001e4d902fc3bf697b439b5 63488dba65ef91373ef616575b32eb0eb21459f4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.14","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.14 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.216 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.183 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.152 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.104 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.45 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.9 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/bridge/br_mrp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"014c062d23c63ec77ef2cf17a0d9363c7441cc94","status":"affected","version":"f7458934b0791c39a001e4d902fc3bf697b439b5","versionType":"git"},{"lessThan":"7ebc23ff03668042e0b0e4034bb1518d36198d9e","status":"affected","version":"f7458934b0791c39a001e4d902fc3bf697b439b5","versionType":"git"},{"lessThan":"06d58b8d2f053ced82e01efaeb6e7c82891eed58","status":"affected","version":"f7458934b0791c39a001e4d902fc3bf697b439b5","versionType":"git"},{"lessThan":"a5e385eeb2d6dbbbdebfa050e67c34734ae12693","status":"affected","version":"f7458934b0791c39a001e4d902fc3bf697b439b5","versionType":"git"},{"lessThan":"5912cf1822fbe53ae275c147868740eb384a5d3e","status":"affected","version":"f7458934b0791c39a001e4d902fc3bf697b439b5","versionType":"git"},{"lessThan":"e08665218040f8e312abe40f74543186f3c2c941","status":"affected","version":"f7458934b0791c39a001e4d902fc3bf697b439b5","versionType":"git"},{"lessThan":"63488dba65ef91373ef616575b32eb0eb21459f4","status":"affected","version":"f7458934b0791c39a001e4d902fc3bf697b439b5","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/bridge/br_mrp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.14"},{"lessThan":"5.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.216","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.183","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.152","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.104","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.45","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.216","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.183","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.152","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.104","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.45","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.9","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"5.14","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: mrp: fix uninitialised bytes on the wire\n\nbr_mrp_alloc_test_skb() builds MRP test frames on an skb from\ndev_alloc_skb(), which does not clear the linear data area.  On the MRA\nring-role branch the sub-option TLV header is appended with\n\n\tsub_tlv = skb_put(skb, sizeof(*sub_tlv));\n\tsub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR;\n\nso sub_tlv->length is never written, and the two trailing alignment bytes\nare appended with a bare skb_put() that does not clear them either.  The\nneighbouring oui and sub_opt regions are explicitly zeroed, so three\nuninitialised bytes are left in every MRA MRP_Test frame that goes out.\n\nPut the sub-option TLV header and the alignment padding in a single\nskb_put_zero(), which clears both.  The AUTO_MGR sub-TLV carries no\npayload, so the zeroed length field is already the value it should have."}],"providerMetadata":{"dateUpdated":"2026-08-22T15:32:32.926Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/014c062d23c63ec77ef2cf17a0d9363c7441cc94"},{"url":"https://git.kernel.org/stable/c/7ebc23ff03668042e0b0e4034bb1518d36198d9e"},{"url":"https://git.kernel.org/stable/c/06d58b8d2f053ced82e01efaeb6e7c82891eed58"},{"url":"https://git.kernel.org/stable/c/a5e385eeb2d6dbbbdebfa050e67c34734ae12693"},{"url":"https://git.kernel.org/stable/c/5912cf1822fbe53ae275c147868740eb384a5d3e"},{"url":"https://git.kernel.org/stable/c/e08665218040f8e312abe40f74543186f3c2c941"},{"url":"https://git.kernel.org/stable/c/63488dba65ef91373ef616575b32eb0eb21459f4"}],"title":"net: bridge: mrp: fix uninitialised bytes on the wire","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74659","datePublished":"2026-08-22T15:32:32.926Z","dateReserved":"2026-08-15T05:44:03.924Z","dateUpdated":"2026-08-22T15:32:32.926Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-22 16:16:39","lastModifiedDate":"2026-08-22 16:16:39","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74659","Ordinal":"1","Title":"net: bridge: mrp: fix uninitialised bytes on the wire","CVE":"CVE-2026-74659","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74659","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: mrp: fix uninitialised bytes on the wire\n\nbr_mrp_alloc_test_skb() builds MRP test frames on an skb from\ndev_alloc_skb(), which does not clear the linear data area.  On the MRA\nring-role branch the sub-option TLV header is appended with\n\n\tsub_tlv = skb_put(skb, sizeof(*sub_tlv));\n\tsub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR;\n\nso sub_tlv->length is never written, and the two trailing alignment bytes\nare appended with a bare skb_put() that does not clear them either.  The\nneighbouring oui and sub_opt regions are explicitly zeroed, so three\nuninitialised bytes are left in every MRA MRP_Test frame that goes out.\n\nPut the sub-option TLV header and the alignment padding in a single\nskb_put_zero(), which clears both.  The AUTO_MGR sub-TLV carries no\npayload, so the zeroed length field is already the value it should have.","Type":"Description","Title":"net: bridge: mrp: fix uninitialised bytes on the wire"}]}}}