{"id":"CVE-2026-99059","title":"wireguard: noise: reject response consumption after intermediate initiation","summary":"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 thre…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < fb5ce4c7790c3eeec820302d08d70ecf46af4295","Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < c76a80db593096edf2b3b3972f58b6342a8c6c04","Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < 4d64a3d6e96aa78619c9c29ffde309794974588a","Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < 3bec3d32c2a3afd164fc87f95457df2cf9049c20","Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < d0305f8d90029556260c6824b61c493c424eba9e","Linux 5.6"],"published":"2026-10-23","updated":"2026-10-23","sourceUpdated":"2026-10-23T12:22:47.559Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99059","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"}],"tags":["cve.org"],"ingestedAt":"2026-10-23T13:24:55.519Z","slug":"CVE-2026-99059","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < fb5ce4c7790c3eeec820302d08d70ecf46af4295`\n- `Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < c76a80db593096edf2b3b3972f58b6342a8c6c04`\n- `Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < 4d64a3d6e96aa78619c9c29ffde309794974588a`\n- `Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < 3bec3d32c2a3afd164fc87f95457df2cf9049c20`\n- `Linux >= e7096c131e5161fa3b8e52a650d7719d2857adfd < d0305f8d90029556260c6824b61c493c424eba9e`\n- `Linux 5.6`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}