CVE-2026-64089batman-adv: tt: fix negative last_changeset_len
- 9.8CriticalCVSS base score
- 0.55%Exploitation in 30 daysEPSS · top 53% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: batman-adv: tt: fix negative last_changeset_len batadv_piv_tt::last_changeset_len 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_my_tt_response(), last_changeset_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_local_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_my_tt_response().
Timeline
ID reserved
By Linux
Published
- 17 days later
· 17 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.55% · top 53% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – < 6314089acf0ddf64376fdc0b1420695504c73f52
- affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – < 55dc41fe8821e9a849e147255ad572bc933a9d15
- affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – < c424e8519ac78eac5d9f4eecf06208a0d619ec14
- affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – < 22d59c72f4a47ffec121d0610f70d0d70c3c11c8
- affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – < eb235472b52ef36981c5aad330485eaf2382c53b
- affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – < 179eb62506a02d00370bd6478898cb632e10986c
- affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – < d29abf70c665730e249d2ec8e1402095ae26bcee
- affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – < fc92cdfcb295cefa4344d71a527d61b638b7bfc4
- affected 3.1
- unaffected < 3.1
- unaffected 5.10.258 – ≤ 5.10.*
- unaffected 5.15.209 – ≤ 5.15.*
- unaffected 6.1.175 – ≤ 6.1.*
- unaffected 6.6.142 – ≤ 6.6.*
- unaffected 6.12.92 – ≤ 6.12.*
- unaffected 6.18.34 – ≤ 6.18.*
- unaffected 7.0.11 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References8
- https://git.kernel.org/stable/c/6314089acf0ddf64376fdc0b1420695504c73f52 (opens in a new tab)
- https://git.kernel.org/stable/c/55dc41fe8821e9a849e147255ad572bc933a9d15 (opens in a new tab)
- https://git.kernel.org/stable/c/c424e8519ac78eac5d9f4eecf06208a0d619ec14 (opens in a new tab)
- https://git.kernel.org/stable/c/22d59c72f4a47ffec121d0610f70d0d70c3c11c8 (opens in a new tab)
- https://git.kernel.org/stable/c/eb235472b52ef36981c5aad330485eaf2382c53b (opens in a new tab)
- https://git.kernel.org/stable/c/179eb62506a02d00370bd6478898cb632e10986c (opens in a new tab)
- https://git.kernel.org/stable/c/d29abf70c665730e249d2ec8e1402095ae26bcee (opens in a new tab)
- https://git.kernel.org/stable/c/fc92cdfcb295cefa4344d71a527d61b638b7bfc4 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-45774 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64089)Record last updated .