{"id":"CVE-2026-74659","title":"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 da…","summary":"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 da…","severity":"none","published":"2026-08-22","updated":"2026-10-14","sourceUpdated":"2026-10-14T13:10:00.187","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74659","references":[{"url":"https://git.kernel.org/stable/c/014c062d23c63ec77ef2cf17a0d9363c7441cc94","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/06d58b8d2f053ced82e01efaeb6e7c82891eed58","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5912cf1822fbe53ae275c147868740eb384a5d3e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/63488dba65ef91373ef616575b32eb0eb21459f4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7ebc23ff03668042e0b0e4034bb1518d36198d9e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a5e385eeb2d6dbbbdebfa050e67c34734ae12693","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e08665218040f8e312abe40f74543186f3c2c941","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00215,"epssPercentile":0.10991,"ingestedAt":"2026-10-14T13:30:58.529Z","slug":"CVE-2026-74659","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}