{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68341", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.384Z", "datePublished": "2026-08-10T12:03:17.821Z", "dateUpdated": "2026-08-17T05:03:41.213Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:03:41.213Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: fix use after free in unlock_ovpn()\n\nunlock_ovpn() iterates over the release_list using llist_for_each_entry()\nand drops the peer reference inside the loop body via ovpn_peer_put().\n\nIf this drops the last reference, the peer is eventually freed. However,\nllist_for_each_entry() reads peer->release_entry.next in the loop advance\nexpression, which runs after the body. By that time the peer may have\nalready been freed, resulting in a use after free when advancing to the\nnext list entry.\n\nFix this by using llist_for_each_entry_safe(), which caches the next\npointer before executing the loop body." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - unlock_ovpn() is reached directly from remote-peer activity: a malformed/aborted OpenVPN TCP stream schedules ovpn_tcp_peer_del_work() -> ovpn_peer_del() (tcp.c:154/287/506), peer disconnect hits ovpn_tcp_close(), and remote peers falling silent make ovpn_peer_keepalive_work() queue peers onto release_list. No local action is needed to enter the vulnerable loop.\nAC:L - The attacker controls both the trigger and its repetition rate: a remote peer can force transport errors, reconnects and keepalive expiries arbitrarily often, and in MP mode can control how many peers land on release_list at once, plus generate traffic-driven allocation pressure to influence slab reuse of the freed ovpn_peer.\nPR:L - The vulnerable loop only runs for peers already installed in the kernel, which the openvpn userspace daemon does for a connected client, so the attacker acts as an established (low-privileged) VPN peer rather than an unauthenticated stranger; no administrative rights on the target are needed.\nUI:N - Peer removal and the subsequent list walk happen automatically inside the kernel's TCP error/close handling and keepalive worker; no administrator or user action on the victim host is required.\nS:U - The use-after-free corrupts kernel heap state within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed ovpn_peer is re-read to obtain the next list pointer, so a reclaimed and re-populated slab object lets the attacker steer the walk onto arbitrary memory that is then dereferenced (peer->sock, peer->refcount), yielding a kernel-memory read primitive and disclosure of sensitive kernel data.\nI:H - Continuing the walk onto a stale/attacker-groomed object causes rcu_replace_pointer() writes, lock_sock() and kref_put() (a controlled decrement plus invocation of a release callback) on a bogus struct ovpn_peer, giving heap-spray-based write and control-flow-hijack potential typical of exploitable UAFs.\nA:H - Dereferencing freed or recycled memory as an ovpn_peer reliably produces oops/panic or slab corruption, taking down the VPN gateway kernel; the path is remotely repeatable, so it is a dependable denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ovpn/peer.c" ], "versions": [ { "version": "80747caef33d77f5c1b3d24644e6d7dae69066b5", "lessThan": "5b96227c0e8b212b74838424c929fc889aedb555", "status": "affected", "versionType": "git" }, { "version": "80747caef33d77f5c1b3d24644e6d7dae69066b5", "lessThan": "4cdb209f12a89c5faf9be0c45edb90ccdf65db0c", "status": "affected", "versionType": "git" }, { "version": "80747caef33d77f5c1b3d24644e6d7dae69066b5", "lessThan": "e1ad6fe5db719874efa45b2caf9934552e09fc43", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ovpn/peer.c" ], "versions": [ { "version": "6.16", "status": "affected" }, { "version": "0", "lessThan": "6.16", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "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": "6.16", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/5b96227c0e8b212b74838424c929fc889aedb555" }, { "url": "https://git.kernel.org/stable/c/4cdb209f12a89c5faf9be0c45edb90ccdf65db0c" }, { "url": "https://git.kernel.org/stable/c/e1ad6fe5db719874efa45b2caf9934552e09fc43" } ], "title": "ovpn: fix use after free in unlock_ovpn()", "x_generator": { "engine": "bippy-1.2.0" } } } }