CVE-2026-43033 (GCVE-0-2026-43033)
Vulnerability from cvelistv5
Published
2026-05-01 14:15
Modified
2026-08-05 12:25
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption When decrypting data that is not in-place (src != dst), there is no need to save the high-order sequence bits in dst as it could simply be re-copied from the source. However, the data to be hashed need to be rearranged accordingly. Thanks,
References
Impacted products
Vendor Product Version
Linux Linux Version: 104880a6b470958ddc30e139c41aa4f6ed3a5234
Version: 104880a6b470958ddc30e139c41aa4f6ed3a5234
Version: 104880a6b470958ddc30e139c41aa4f6ed3a5234
Version: 104880a6b470958ddc30e139c41aa4f6ed3a5234
Version: 104880a6b470958ddc30e139c41aa4f6ed3a5234
Version: 104880a6b470958ddc30e139c41aa4f6ed3a5234
Version: 104880a6b470958ddc30e139c41aa4f6ed3a5234
Version: 104880a6b470958ddc30e139c41aa4f6ed3a5234
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption\n\nWhen decrypting data that is not in-place (src != dst), there is\nno need to save the high-order sequence bits in dst as it could\nsimply be re-copied from the source.\n\nHowever, the data to be hashed need to be rearranged accordingly.\n\n\nThanks,"
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              "value": "AV:L - The vulnerable out-of-place AEAD decrypt path is reachable by a local process through AF_ALG sockets using authencesn, while normal inbound ESP uses in-place src==dst. This requires local syscall access rather than remote packets directly reaching the bad branch.\nAC:L - The attacker controls the AF_ALG request buffers, associated-data length, operation type, key, and authsize, and no race or hard-to-influence state is required. The fault occurs before ICV verification, so a valid packet/tag is not needed.\nPR:L - AF_ALG socket creation, bind, key setup, and AEAD decrypt do not require CAP_NET_ADMIN or CAP_SYS_ADMIN, but the attacker needs local unprivileged code execution. XFRM state management is privileged, but the lower-privilege AF_ALG path reaches the bug.\nUI:N - No victim action is required once the local attacker runs the AF_ALG syscall sequence. The attacker supplies both input and output buffers directly.\nS:U - The vulnerability is in kernel crypto processing and impacts the same kernel security authority. It does not cross a VM, IOMMU, or other separate security boundary.\nC:H - The bug is a kernel memory-corruption condition from writing ESN high sequence bytes past the intended out-of-place destination; successful exploitation of such corruption could expose arbitrary kernel memory. Under the required uncertainty rule, this is scored as high confidentiality impact.\nI:H - The vulnerable code performs an attacker-influenced out-of-bounds write of four bytes before authentication succeeds. Kernel out-of-bounds writes are scored as high integrity impact because they can plausibly be shaped into control-flow or data corruption.\nA:H - At minimum, the AF_ALG path can drive scatterwalk past the end of the destination scatterlist and crash the kernel. A local attacker can repeat the trigger without authentication, causing high availability impact."
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    "cveId": "CVE-2026-43033",
    "datePublished": "2026-05-01T14:15:32.583Z",
    "dateReserved": "2026-05-01T14:12:55.977Z",
    "dateUpdated": "2026-08-05T12:25:26.050Z",
    "state": "PUBLISHED"
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}


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