{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-53389", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.402Z", "datePublished": "2026-07-19T12:01:54.386Z", "dateUpdated": "2026-08-17T04:50:40.399Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:50:40.399Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp-ao: fix use-after-free of key in del_async path\n\nIn tcp_ao_delete_key(), the del_async path skips the current_key\nand rnext_key validity checks present in the synchronous path,\nassuming these pointers are always NULL on LISTEN sockets. However,\nif a key was added with set_current=1/set_rnext=1 while the socket\nwas in CLOSE state, current_key and rnext_key will be non-NULL\nafter listen() transitions the socket to LISTEN.\n\nWhen such a key is deleted with del_async=1, hlist_del_rcu() and\ncall_rcu() free the key without clearing the dangling pointers.\nAfter the RCU grace period, getsockopt(TCP_AO_INFO) dereferences\ncurrent_key->sndid and rnext_key->rcvid from freed slab memory.\n\nClear current_key and rnext_key in the del_async path when they\nreference the key being deleted." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - Exploitation requires local `setsockopt`/`getsockopt` syscalls on a TCP socket owned by the attacker; the UAF is triggered in socket-option management, not by remote TCP-AO packet processing on the listen path.\nAC:L - An attacker who controls the socket can deterministically perform add-with-set_current/set_rnext on CLOSE, listen(), del_async delete, wait for RCU, then getsockopt(TCP_AO_INFO) without depending on conditions outside their control.\nPR:L - No capability checks protect TCP-AO socket options beyond socket ownership; an unprivileged local user (including in a user namespace) can create a listening TCP socket, configure TCP-AO keys, and trigger the bug on their own socket.\nUI:N - No victim interaction is required; the attacker drives the full exploit sequence through their own socket file descriptor.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the same security domain; this is not a cross-VM, cross-container, or IOMMU boundary escape.\nC:H - The bug is a use-after-free where `getsockopt(TCP_AO_INFO)` reads `sndid`/`rcvid` from freed `tcp_ao_key` slab memory, enabling information disclosure from attacker-influenced freed heap contents.\nI:H - Use-after-free of a heap-allocated `tcp_ao_key` structure can be leveraged with heap grooming for arbitrary memory corruption and potential kernel code execution, not merely a bounded write.\nA:H - Dereferencing freed kernel memory via `getsockopt(TCP_AO_INFO)` can cause kernel oops/panic and denial of service even when full exploitation is not attempted." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv4/tcp_ao.c" ], "versions": [ { "version": "d6732b95b6fbbc6d5bb9d2f809e275763640c4a2", "lessThan": "6ce7ef41743740ce15c2061561b784148b565b3f", "status": "affected", "versionType": "git" }, { "version": "d6732b95b6fbbc6d5bb9d2f809e275763640c4a2", "lessThan": "e77fbefd1269b5c123e7c651a1ebdce1b87d19a0", "status": "affected", "versionType": "git" }, { "version": "d6732b95b6fbbc6d5bb9d2f809e275763640c4a2", "lessThan": "7ddc29a094d96e9b3aa280433c6dc443df9eabf2", "status": "affected", "versionType": "git" }, { "version": "d6732b95b6fbbc6d5bb9d2f809e275763640c4a2", "lessThan": "5ba9950bc9078e19b69cca1e56d1553b125c6857", "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/ipv4/tcp_ao.c" ], "versions": [ { "version": "6.7", "status": "affected" }, { "version": "0", "lessThan": "6.7", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.95", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.38", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.3", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.7", "versionEndExcluding": "6.12.95" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.18.38" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "7.1.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6ce7ef41743740ce15c2061561b784148b565b3f" }, { "url": "https://git.kernel.org/stable/c/e77fbefd1269b5c123e7c651a1ebdce1b87d19a0" }, { "url": "https://git.kernel.org/stable/c/7ddc29a094d96e9b3aa280433c6dc443df9eabf2" }, { "url": "https://git.kernel.org/stable/c/5ba9950bc9078e19b69cca1e56d1553b125c6857" } ], "title": "net/tcp-ao: fix use-after-free of key in del_async path", "x_generator": { "engine": "bippy-1.2.0" } } } }