CVE-2026-64088 (GCVE-0-2026-64088)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-07-20 13:43
VLAI
Title
batman-adv: tt: fix negative tt_buff_len
Summary
In the Linux kernel, the following vulnerability has been resolved: batman-adv: tt: fix negative tt_buff_len batadv_orig_node::tt_buff_len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer. In batadv_send_other_tt_response(), tt_buff_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_global_data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized. Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv_send_other_tt_response().
Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: a73105b8d4c765d9ebfb664d0a66802127d8e4c7 , < 4c4c2f340f4c27373bfcac8dc5032ce7bb474e47 (git)
Affected: a73105b8d4c765d9ebfb664d0a66802127d8e4c7 , < 33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430 (git)
Affected: a73105b8d4c765d9ebfb664d0a66802127d8e4c7 , < 3c96dff00998314983b68a3e7caac07a66ebe496 (git)
Affected: a73105b8d4c765d9ebfb664d0a66802127d8e4c7 , < 32edd2a28e112064020a2f319a8cb8a9e5a09767 (git)
Affected: a73105b8d4c765d9ebfb664d0a66802127d8e4c7 , < 4dab98961426d0cf6a1599cda6950b7596ca2fcd (git)
Affected: a73105b8d4c765d9ebfb664d0a66802127d8e4c7 , < 730de8733dd90f70d7580a9b329b971f8e1474a2 (git)
Affected: a73105b8d4c765d9ebfb664d0a66802127d8e4c7 , < ed28ead3420c373a7928622f114bc6168075d1e1 (git)
Affected: a73105b8d4c765d9ebfb664d0a66802127d8e4c7 , < b64963a2ceeb7529310b6cf253a1e540784422f4 (git)
Create a notification for this product.
Linux Linux Affected: 3.1
Unaffected: 0 , < 3.1 (semver)
Unaffected: 5.10.258 , ≤ 5.10.* (semver)
Unaffected: 5.15.209 , ≤ 5.15.* (semver)
Unaffected: 6.1.175 , ≤ 6.1.* (semver)
Unaffected: 6.6.142 , ≤ 6.6.* (semver)
Unaffected: 6.12.92 , ≤ 6.12.* (semver)
Unaffected: 6.18.34 , ≤ 6.18.* (semver)
Unaffected: 7.0.11 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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                  "versionStartIncluding": "3.1",
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          "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()."
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64088",
    "datePublished": "2026-07-19T15:39:58.084Z",
    "dateReserved": "2026-07-19T07:54:57.032Z",
    "dateUpdated": "2026-07-20T13:43:11.384Z",
    "state": "PUBLISHED"
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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().\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/batman-adv/types.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"a73105b8d4c765d9ebfb664d0a66802127d8e4c7\",\"lessThan\":\"4c4c2f340f4c27373bfcac8dc5032ce7bb474e47\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"a73105b8d4c765d9ebfb664d0a66802127d8e4c7\",\"lessThan\":\"33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"a73105b8d4c765d9ebfb664d0a66802127d8e4c7\",\"lessThan\":\"3c96dff00998314983b68a3e7caac07a66ebe496\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"a73105b8d4c765d9ebfb664d0a66802127d8e4c7\",\"lessThan\":\"32edd2a28e112064020a2f319a8cb8a9e5a09767\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"a73105b8d4c765d9ebfb664d0a66802127d8e4c7\",\"lessThan\":\"4dab98961426d0cf6a1599cda6950b7596ca2fcd\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"a73105b8d4c765d9ebfb664d0a66802127d8e4c7\",\"lessThan\":\"730de8733dd90f70d7580a9b329b971f8e1474a2\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"a73105b8d4c765d9ebfb664d0a66802127d8e4c7\",\"lessThan\":\"ed28ead3420c373a7928622f114bc6168075d1e1\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"a73105b8d4c765d9ebfb664d0a66802127d8e4c7\",\"lessThan\":\"b64963a2ceeb7529310b6cf253a1e540784422f4\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/batman-adv/types.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3.1\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"3.1\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.258\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.209\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.175\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.142\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.92\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.34\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.11\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"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\",\"attackVector\":\"ADJACENT_NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/32edd2a28e112064020a2f319a8cb8a9e5a09767\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/3c96dff00998314983b68a3e7caac07a66ebe496\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/4c4c2f340f4c27373bfcac8dc5032ce7bb474e47\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/4dab98961426d0cf6a1599cda6950b7596ca2fcd\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/730de8733dd90f70d7580a9b329b971f8e1474a2\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b64963a2ceeb7529310b6cf253a1e540784422f4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ed28ead3420c373a7928622f114bc6168075d1e1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-07-21T06:23:03+00:00",
      "cve": "CVE-2026-64088",
      "id": "CVE-2026-64088",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: batman-adv: tt: fix negative tt_buff_len",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64088.json",
      "version": "3"
    }
  }
}



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Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.