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CVE

CVE-2026-64089

batman-adv: tt: fix negative last_changeset_len
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CVE

CVE-2026-64089

batman-adv: tt: fix negative last_changeset_len

In the Linux kernel, the following vulnerability has been resolved:

batman-adv: tt: fix negative lastchangesetlen

batadvpivtt::lastchangesetlen 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 batadvsendmyttresponse(), lastchangesetlen is temporarily widened

to s32. The incorrectly negative s16 value propagates into the s32, causing

batadvttpreparetvlvlocal_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 batadvsendmyttresponse().

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.8
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
C
H
U
0
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
C
H
U
-

Related Resources

No items found.

References

https://git.kernel.org/stable/c/179eb62506a02d00370bd6478898cb632e10986c, https://git.kernel.org/stable/c/22d59c72f4a47ffec121d0610f70d0d70c3c11c8, https://git.kernel.org/stable/c/55dc41fe8821e9a849e147255ad572bc933a9d15, https://git.kernel.org/stable/c/6314089acf0ddf64376fdc0b1420695504c73f52, https://git.kernel.org/stable/c/c424e8519ac78eac5d9f4eecf06208a0d619ec14, https://git.kernel.org/stable/c/d29abf70c665730e249d2ec8e1402095ae26bcee, https://git.kernel.org/stable/c/eb235472b52ef36981c5aad330485eaf2382c53b, https://git.kernel.org/stable/c/fc92cdfcb295cefa4344d71a527d61b638b7bfc4, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64089.json, https://nvd.nist.gov/vuln/detail/CVE-2026-64089, https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Severity

9.8

CVSS Score
0
10

Basic Information

Base CVSS
9.8
EPSS Probability
0.00552%
EPSS Percentile
0.43914%
Introduced Version
a73105b8d4c765d9ebfb664d0a66802127d8e4c7,3.1.0,5.11.0,5.16.0,6.2.0,6.7.0,6.13.0,6.19.0,0
Fix Available
fc92cdfcb295cefa4344d71a527d61b638b7bfc4,5.10.258,5.15.209,6.1.175,6.6.142,6.12.92,6.18.34,7.0.11,6.1.176-1,6.12.94-1,5.15.0-1112.119~20.04.1,5.15.0-1117.126~20.04.1,5.15.0-1117.126~20.04.2,5.15.0-1112.122~20.04.1,5.15.0-186.196~20.04.1,5.15.0-1106.110~20.04.1,5.15.0-1107.113~20.04.1,5.15.0-184.194~20.04.1,5.15.0-1064.66~20.04.1,5.15.0-1109.115~20.04.1,7.0.0-28.28~24.04.1,7.0.0-1016.16~24.04.1,7.0.0-28.28.1~24.04.3,5.15.0-186.196,5.15.0-1112.119,5.15.0-1117.126,5.15.0-1112.122,5.15.0-1108.114,5.15.0-1095.103,5.15.0-1106.110,5.15.0-1107.113,5.15.0-1104.109,5.15.0-184.194,5.15.0-1107.108,5.15.0-1064.66,5.15.0-1053.53,5.15.0-1109.115,5.15.0-1075.79,0:5.15.0-323.211.3.3.el8uek,0:5.15.0-323.211.3.3.el9uek

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