{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/net/vxlan/vxlan_mdb.c", "tools/testing/selftests/net/test_vxlan_mdb.sh"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "069d5527bb0f229e528fa88c6b72f15060c373f2", "status": "affected", "version": "a3a48de5eade770e911d35291217bdd69ce04ef1", "versionType": "git"}, {"lessThan": "e12c903fd13c6261b98ca18d8f70ac26e739e2f8", "status": "affected", "version": "a3a48de5eade770e911d35291217bdd69ce04ef1", "versionType": "git"}, {"lessThan": "74e2a56c82209b0335b53e25f19f9b0590e2483d", "status": "affected", "version": "a3a48de5eade770e911d35291217bdd69ce04ef1", "versionType": "git"}, {"lessThan": "71203a41d6fa2fa0ea2f3a7541987958bd3694fd", "status": "affected", "version": "a3a48de5eade770e911d35291217bdd69ce04ef1", "versionType": "git"}, {"lessThan": "4aa61c88b4e292e10abdfd791334b8272108d68a", "status": "affected", "version": "a3a48de5eade770e911d35291217bdd69ce04ef1", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/net/vxlan/vxlan_mdb.c", "tools/testing/selftests/net/test_vxlan_mdb.sh"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.4"}, {"lessThan": "6.4", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.158", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.111", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.53", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.7", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "0E70134D-9B4B-43A0-B5C8-9DCEDD74AB69", "versionEndExcluding": "6.6.158", "versionStartIncluding": "6.4", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "47BC31C9-3D9E-4B96-B5F8-291D6AD55D81", "versionEndExcluding": "6.12.111", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "7561AABB-6D5A-4324-BC66-C6C6B012AFD8", "versionEndExcluding": "6.18.53", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "19917B2D-B4B2-4416-A482-9C7C4929A921", "versionEndExcluding": "7.2.7", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.3:rc1:*:*:*:*:*:*", "matchCriteriaId": "11E35E1B-5DB4-4AB9-9706-CD73B799EADF", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del()\n\nvxlan_mdb_is_valid_source(), which validates MDBE_ATTR_SOURCE and every\nMDBE_ATTR_SRC_LIST member, accepts the all-zeros address.\n\nA source list is only accepted on a (*, G) entry, whose source is the\nall-zeros address, and for each member of the list an (S, G) entry is\nderived from it by substituting the source. Entries are keyed by a plain\nmemcmp() of struct vxlan_mdb_entry_key, so if MDBE_ATTR_SOURCE is present\nand holds the all-zeros address and the source list holds it as well, the\nderived (S, G) key is byte-identical to the (*, G) key and resolves to the\nsame entry. Omitting MDBE_ATTR_SOURCE is not equivalent, as the key is\nthen left with a zero address family.\n\nvxlan_mdb_remote_src_del() removes the forwarding entry of a source before\nfreeing the source entry:\n\n\tvxlan_mdb_remote_src_fwd_del(vxlan, group, remote, &ent->addr);\n\tvxlan_mdb_remote_src_entry_del(ent);\n\nWith the keys aliased, the first call deletes the remote of the entry that\nowns 'ent' instead of a separate (S, G) entry, and frees 'ent'. The second\ncall then runs on the freed entry, and its hlist_del() reads ->pprev and\n->next out of it and writes through them.\n\nAdding the (*, G) entry with NLM_F_REPLACE and no source list marks the\nall-zeros source for deletion and reaches this from the sweep at the end\nof vxlan_mdb_remote_srcs_replace().\n\n BUG: KASAN: slab-use-after-free in __vxlan_mdb_add+0x1cd/0xd70\n Read of size 8 at addr ffff888102852500 by task poc/84\n __vxlan_mdb_add+0x1cd/0xd70\n vxlan_mdb_add+0xc0/0x140\n rtnl_mdb_add+0x157/0x2a0\n rtnetlink_rcv_msg+0x207/0x5a0\n Allocated by task 84:\n __kmalloc_cache_noprof+0x153/0x360\n vxlan_mdb_remote_srcs_add+0x2eb/0x440\n __vxlan_mdb_add+0x803/0xd70\n Freed by task 84:\n kfree+0x14c/0x3b0\n vxlan_mdb_remote_del+0x129/0x1a0\n __vxlan_mdb_del+0x4f/0xe0\n vxlan_mdb_remote_src_fwd_del.isra.0+0x162/0x1b0\n __vxlan_mdb_add+0x1c5/0xd70\n\nThe MDB operations are netns-scoped, so an unprivileged user can perform\nthem in a new user and network namespace.\n\nReject the all-zeros address in vxlan_mdb_is_valid_source(), which covers\nboth call sites. A (*, G) entry is expressed by omitting the source, so\nnothing legitimate is refused.\n\nDiscovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>"}], "id": "CVE-2026-98122", "lastModified": "2026-10-22T17:19:22.093", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-25T11:17:43.470", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/069d5527bb0f229e528fa88c6b72f15060c373f2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4aa61c88b4e292e10abdfd791334b8272108d68a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/71203a41d6fa2fa0ea2f3a7541987958bd3694fd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/74e2a56c82209b0335b53e25f19f9b0590e2483d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e12c903fd13c6261b98ca18d8f70ac26e739e2f8"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}]}