{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64088", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.032Z", "datePublished": "2026-07-19T15:39:58.084Z", "dateUpdated": "2026-08-05T12:39:05.060Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:39:05.060Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: tt: fix negative tt_buff_len\n\nbatadv_orig_node::tt_buff_len was declared as s16, but the field is never\nintended to hold a negative value. When a value greater than 32767 is\nassigned, it wraps to a negative signed integer.\n\nIn batadv_send_other_tt_response(), tt_buff_len is temporarily widened to\ns32. The incorrectly negative s16 value propagates into the s32, causing\nbatadv_tt_prepare_tvlv_global_data() to allocate a full sized buffer but\npopulates only a small portion of it with the collected changeset. All\nremaining bits are kept uninitialized.\n\nUsing an u16 avoids this type confusion and ensures that no (negative) sign\nextension is performed in batadv_send_other_tt_response()." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:A - Batman-adv processes attacker-controlled translation-table TVLV traffic from mesh peers over WiFi/Ethernet L2; exploitation requires the attacker to be on the same wireless or LAN segment as the victim mesh node, matching the Adjacent definition for WiFi/L2 mesh protocols.\nAC:L - An adjacent mesh attacker can send unauthenticated TT_REQUEST/TT_RESPONSE/OGM TVLV packets to populate `tt_buff_len` and then trigger `batadv_send_other_tt_response()` without depending on victim-controlled timing or memory layout.\nPR:N - The vulnerable path is reached from pre-authentication mesh control-plane packet handling (`batadv_recv_unicast_tvlv` → `batadv_tt_tvlv_unicast_handler_v1`); no Linux credentials or capabilities are required on the victim host beyond having an active batman-adv mesh interface.\nUI:N - Exploitation requires only crafted mesh protocol packets from an adjacent attacker; no victim user action (opening files, clicking links, etc.) is needed at attack time.\nS:U - Impact is confined to kernel memory disclosure/corruption and potential local privilege escalation within the same kernel security authority; it does not cross VM, container, or IOMMU boundaries.\nC:H - Sign-extended negative `tt_buff_len` causes `batadv_tt_prepare_tvlv_global_data()` to allocate a large buffer but only partially fill it, leaving the remainder uninitialized and transmitted to the requester in the TT_RESPONSE via `batadv_tvlv_unicast_send()`.\nI:H - The same type confusion passes a negative `s16` length to `memcpy()`, which promotes to a very large `size_t` and can cause out-of-bounds reads/writes from the undersized `tt_buff` allocation, enabling heap memory corruption.\nA:H - The malformed `memcpy()` and associated heap corruption can trigger kernel oops/panic on the responding mesh node, and the bug class inherently threatens system availability even when not fully weaponized." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/batman-adv/types.h" ], "versions": [ { "version": "a73105b8d4c765d9ebfb664d0a66802127d8e4c7", "lessThan": "4c4c2f340f4c27373bfcac8dc5032ce7bb474e47", "status": "affected", "versionType": "git" }, { "version": "a73105b8d4c765d9ebfb664d0a66802127d8e4c7", "lessThan": "33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430", "status": "affected", "versionType": "git" }, { "version": "a73105b8d4c765d9ebfb664d0a66802127d8e4c7", "lessThan": "3c96dff00998314983b68a3e7caac07a66ebe496", "status": "affected", "versionType": "git" }, { "version": "a73105b8d4c765d9ebfb664d0a66802127d8e4c7", "lessThan": "32edd2a28e112064020a2f319a8cb8a9e5a09767", "status": "affected", "versionType": "git" }, { "version": "a73105b8d4c765d9ebfb664d0a66802127d8e4c7", "lessThan": "4dab98961426d0cf6a1599cda6950b7596ca2fcd", "status": "affected", "versionType": "git" }, { "version": "a73105b8d4c765d9ebfb664d0a66802127d8e4c7", "lessThan": "730de8733dd90f70d7580a9b329b971f8e1474a2", "status": "affected", "versionType": "git" }, { "version": "a73105b8d4c765d9ebfb664d0a66802127d8e4c7", "lessThan": "ed28ead3420c373a7928622f114bc6168075d1e1", "status": "affected", "versionType": "git" }, { "version": "a73105b8d4c765d9ebfb664d0a66802127d8e4c7", "lessThan": "b64963a2ceeb7529310b6cf253a1e540784422f4", "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/batman-adv/types.h" ], "versions": [ { "version": "3.1", "status": "affected" }, { "version": "0", "lessThan": "3.1", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.142", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "3.1", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4c4c2f340f4c27373bfcac8dc5032ce7bb474e47" }, { "url": "https://git.kernel.org/stable/c/33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430" }, { "url": "https://git.kernel.org/stable/c/3c96dff00998314983b68a3e7caac07a66ebe496" }, { "url": "https://git.kernel.org/stable/c/32edd2a28e112064020a2f319a8cb8a9e5a09767" }, { "url": "https://git.kernel.org/stable/c/4dab98961426d0cf6a1599cda6950b7596ca2fcd" }, { "url": "https://git.kernel.org/stable/c/730de8733dd90f70d7580a9b329b971f8e1474a2" }, { "url": "https://git.kernel.org/stable/c/ed28ead3420c373a7928622f114bc6168075d1e1" }, { "url": "https://git.kernel.org/stable/c/b64963a2ceeb7529310b6cf253a1e540784422f4" } ], "title": "batman-adv: tt: fix negative tt_buff_len", "x_generator": { "engine": "bippy-1.2.0" } } } }