CVE-2026-64088 (CVSS 8.8)

Description

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().

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CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0029

Probability of exploitation

0.21%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/32edd2a28e112064020a2f319a8cb8a9e5a09767 https://git.kernel.org/stable/c/33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430 https://git.kernel.org/stable/c/3c96dff00998314983b68a3e7caac07a66ebe496 https://git.kernel.org/stable/c/4c4c2f340f4c27373bfcac8dc5032ce7bb474e47 https://git.kernel.org/stable/c/4dab98961426d0cf6a1599cda6950b7596ca2fcd https://git.kernel.org/stable/c/730de8733dd90f70d7580a9b329b971f8e1474a2 https://git.kernel.org/stable/c/b64963a2ceeb7529310b6cf253a1e540784422f4 https://git.kernel.org/stable/c/ed28ead3420c373a7928622f114bc6168075d1e1

Frequently Asked Questions

What is CVE-2026-64088? +

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(). It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-64088? +

CVE-2026-64088 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0029, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-64088? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-64088