{ "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": "2026-10-15T01:20:24.801Z" }, "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" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-10-15T01:20:24.801Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html" }, { "url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html" }, { "url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html" } ] } ] } }