{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-99059", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.388Z", "datePublished": "2026-10-23T12:22:47.559Z", "dateUpdated": "2026-10-24T14:10:16.832Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-24T14:10:16.832Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwireguard: noise: reject response consumption after intermediate initiation\n\nTwo threads begin processing the identical response message, received\ntwice. The first thread, A, runs. While it's running, the second one,\nB, gets partway through, and during that slow calculation, or even while\nblocking on down_write(), A completes and then also a handshake\ninitiation that's already been queued up runs in thread C, which itself\ntakes that same down_write(). The handshake initiation creation\nsucceeds, and sets the state back to waiting-for-response, and calls\nup_write(), at which point thread B resumes, because either its finished\nits calculations or was finally allowed to acquire down_write(). Thread\nB then copies the state back to the peer, and begins a new session,\nusing that state, which is the same session as the one made in thread A.\n\nThread A\t\t\tThread B\t\t\tThread C\n\ndown_read()\n sA = handshake->state\n memcpy(cA, handshake->crypto)\nup_read()\nif (sA != 1)\n goto fail\nslow_crypto(cA)\n\t\t\t\tdown_read()\n\t\t\t\t sB = handshake->state\n\t\t\t\t memcpy(cB, handshake->crypto)\n\t\t\t\tup_read()\n\t\t\t\tif (sB != 1)\n\t\t\t\t goto fail\n\t\t\t\tslow_crypto(cB)\ndown_write()\n if (sA != handshake->state)\n goto fail\n memcpy(handshake->crypto, cA)\n handshake->state = 2\nup_write()\ndown_write()\n if (handshake->state != 2)\n goto fail\n derive_session(handshake->crypto)\nup_write()\n\t\t\t\t\t\t\t\tdown_write()\n\t\t\t\t\t\t\t\t slow_crypto(handshake->crypto)\n\t\t\t\t\t\t\t\t handshake->state = 1\n\t\t\t\t\t\t\t\tup_write()\n\t\t\t\tdown_write()\n\t\t\t\t if (sB != handshake->state)\n\t\t\t\t goto fail\n\t\t\t\t memcpy(handshake->crypto, cB)\n\t\t\t\t handshake->state = 2\n\t\t\t\tup_write()\n\t\t\t\tdown_write()\n\t\t\t\t if (handshake->state != 2)\n\t\t\t\t goto fail\n\t\t\t\t derive_session(handshake->crypto)\n\t\t\t\tup_write()\n\nThis seems basically impossible to hit in a meaningful way in practice,\nbut ensure that it absolutely cannot happen by comparing the ephemeral\nprivate key that's on the stack with the latest one that the peer's\nhandshake state has." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L", "baseScore": 7.7, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - An IPv4/IPv6 UDP MESSAGE_HANDSHAKE_RESPONSE follows wg_receive() -> wg_packet_receive() -> wg_packet_handshake_receive_worker() -> wg_receive_handshake_packet() -> patched wg_noise_handshake_consume_response(); replayed response bytes drive the race over a routable WireGuard endpoint.\nAC:H - Success requires responses A and B to snapshot the same initiation while a jittered retransmission has queued C, followed by the exact A-to-C-to-B write-lock ordering. The random REKEY_TIMEOUT jitter and host worker scheduling are not controlled by the attacker.\nPR:N - A byte-identical captured response passes wg_cookie_validate_packet() and the encrypted_nothing check in message_decrypt() when replayed, so an on-path attacker need not possess a configured peer's private or preshared key.\nUI:N - The attacker delays and duplicates the UDP response, while wg_expired_retransmit_handshake() automatically queues the intermediate initiation; no victim action is required during exploitation.\nS:U - The duplicate sessions remain within the same peer's noise_keypairs and compromise traffic handled by that WireGuard device under the same kernel security authority; no VM, IOMMU, or other authority boundary is crossed.\nC:H - Both calls to wg_noise_handshake_begin_session() run derive_keys() on the same chaining_key, while each keypair_create() starts sending_counter at zero. Reusing ChaCha20 keys and nonces across transport packets can expose substantial tunnel plaintext.\nI:H - encrypt_packet() authenticates transport ciphertext with ChaCha20-Poly1305 using the duplicated key and reset counter as its nonce. Reusing that Poly1305 one-time key permits an on-path attacker to construct forged authenticated tunnel packets for colliding counters.\nA:L - The reset sending_counter repeats counters already used by the first session, so the peer's counter_validate() replay window discards colliding packets until the new counter catches up or a rekey occurs. This interrupts tunnel traffic but does not corrupt memory or crash the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/wireguard/noise.c" ], "versions": [ { "version": "e7096c131e5161fa3b8e52a650d7719d2857adfd", "lessThan": "fb5ce4c7790c3eeec820302d08d70ecf46af4295", "status": "affected", "versionType": "git" }, { "version": "e7096c131e5161fa3b8e52a650d7719d2857adfd", "lessThan": "c76a80db593096edf2b3b3972f58b6342a8c6c04", "status": "affected", "versionType": "git" }, { "version": "e7096c131e5161fa3b8e52a650d7719d2857adfd", "lessThan": "4d64a3d6e96aa78619c9c29ffde309794974588a", "status": "affected", "versionType": "git" }, { "version": "e7096c131e5161fa3b8e52a650d7719d2857adfd", "lessThan": "3bec3d32c2a3afd164fc87f95457df2cf9049c20", "status": "affected", "versionType": "git" }, { "version": "e7096c131e5161fa3b8e52a650d7719d2857adfd", "lessThan": "d0305f8d90029556260c6824b61c493c424eba9e", "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/wireguard/noise.c" ], "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.113", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.11", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "5.6", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.12.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.18.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.2.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/fb5ce4c7790c3eeec820302d08d70ecf46af4295" }, { "url": "https://git.kernel.org/stable/c/c76a80db593096edf2b3b3972f58b6342a8c6c04" }, { "url": "https://git.kernel.org/stable/c/4d64a3d6e96aa78619c9c29ffde309794974588a" }, { "url": "https://git.kernel.org/stable/c/3bec3d32c2a3afd164fc87f95457df2cf9049c20" }, { "url": "https://git.kernel.org/stable/c/d0305f8d90029556260c6824b61c493c424eba9e" } ], "title": "wireguard: noise: reject response consumption after intermediate initiation", "x_generator": { "engine": "bippy-1.2.0" } } } }