{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46086","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-13T15:03:33.096Z","datePublished":"2026-05-27T12:58:28.137Z","dateUpdated":"2026-06-19T11:59:23.674Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-06-19T11:59:23.674Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: use a stable FDB dst snapshot in RCU readers\n\nLocal FDB entries can be rewritten in place by `fdb_delete_local()`, which\nupdates `f->dst` to another port or to `NULL` while keeping the entry\nalive. Several bridge RCU readers inspect `f->dst`, including\n`br_fdb_fillbuf()` through the `brforward_read()` sysfs path.\n\nThese readers currently load `f->dst` multiple times and can therefore\nobserve inconsistent values across the check and later dereference.\nIn `br_fdb_fillbuf()`, this means a concurrent local-FDB update can change\n`f->dst` after the NULL check and before the `port_no` dereference,\nleading to a NULL-ptr-deref.\n\nFix this by taking a single `READ_ONCE()` snapshot of `f->dst` in each\naffected RCU reader and using that snapshot for the rest of the access\nsequence. Also publish the in-place `f->dst` updates in `fdb_delete_local()`\nwith `WRITE_ONCE()` so the readers and writer use matching access patterns."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bridge/br_arp_nd_proxy.c","net/bridge/br_fdb.c"],"versions":[{"version":"960b589f86c74ce582922fcb996103271081f4de","lessThan":"c502fa9f094cb03d1d1685c71e2105ab359bc2b8","status":"affected","versionType":"git"},{"version":"960b589f86c74ce582922fcb996103271081f4de","lessThan":"a6ae4511c07b91f597e461406c6330f0d4ff810e","status":"affected","versionType":"git"},{"version":"960b589f86c74ce582922fcb996103271081f4de","lessThan":"1406c4e0ed1eaf8a29801ab1163d00fb7ee4359a","status":"affected","versionType":"git"},{"version":"960b589f86c74ce582922fcb996103271081f4de","lessThan":"0b9e4bbfb7c949151e3acd44ed4aa33614d2e110","status":"affected","versionType":"git"},{"version":"960b589f86c74ce582922fcb996103271081f4de","lessThan":"81af4137a30c4c2dc694dea8cacb180bd66000ef","status":"affected","versionType":"git"},{"version":"960b589f86c74ce582922fcb996103271081f4de","lessThan":"5424e678f9b304e148cf5dcc047cffc7a56a3bb5","status":"affected","versionType":"git"},{"version":"960b589f86c74ce582922fcb996103271081f4de","lessThan":"9a2d9d4e657b23dc21f24cf139e3aeff0b61341f","status":"affected","versionType":"git"},{"version":"960b589f86c74ce582922fcb996103271081f4de","lessThan":"df4601653201de21b487c3e7fffd464790cab808","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bridge/br_arp_nd_proxy.c","net/bridge/br_fdb.c"],"versions":[{"version":"3.14","status":"affected"},{"version":"0","lessThan":"3.14","status":"unaffected","versionType":"semver"},{"version":"5.10.259","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.210","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.176","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.140","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.86","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.27","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.4","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"5.10.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"5.15.210"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"6.6.140"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"6.12.86"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"6.18.27"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"7.0.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/c502fa9f094cb03d1d1685c71e2105ab359bc2b8"},{"url":"https://git.kernel.org/stable/c/a6ae4511c07b91f597e461406c6330f0d4ff810e"},{"url":"https://git.kernel.org/stable/c/1406c4e0ed1eaf8a29801ab1163d00fb7ee4359a"},{"url":"https://git.kernel.org/stable/c/0b9e4bbfb7c949151e3acd44ed4aa33614d2e110"},{"url":"https://git.kernel.org/stable/c/81af4137a30c4c2dc694dea8cacb180bd66000ef"},{"url":"https://git.kernel.org/stable/c/5424e678f9b304e148cf5dcc047cffc7a56a3bb5"},{"url":"https://git.kernel.org/stable/c/9a2d9d4e657b23dc21f24cf139e3aeff0b61341f"},{"url":"https://git.kernel.org/stable/c/df4601653201de21b487c3e7fffd464790cab808"}],"title":"net: bridge: use a stable FDB dst snapshot in RCU readers","x_generator":{"engine":"bippy-1.2.0"}}}}