CVE-2026-64089
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().
CSIRTS triage
- What
- Multiple kernel flaws including NTFS file system out-of-bounds read, AMD processor floating point unit data exposure, and AMD Zen 2 operation cache isolation failure.
- Who is affected
- Systems running affected Linux kernel versions; local attackers on systems with NTFS mounted or AMD processors.
- Urgency
- Moderate to high — local attackers can gain privilege escalation and information disclosure; apply patches promptly.
- Action
- Apply kernel security updates provided by distribution maintainer.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.55% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 44% of all EPSS-scored CVEs.
Advisory coverage (19)
- unknownUSN-8729-1: Linux kernel vulnerabilitiesubuntu · 2026-09-07
- unknownexploitedUSN-8728-1: Linux kernel (GCP) vulnerabilitiesubuntu · 2026-09-07
- unknownUSN-8668-1: Linux kernel (GCP) vulnerabilitiesubuntu · 2026-08-21
- unknownUSN-8664-1: Linux kernel (NVIDIA BaseOS) vulnerabilitiesubuntu · 2026-08-20
- unknownUSN-8663-1: Linux kernel (NVIDIA) vulnerabilitiesubuntu · 2026-08-20
- unknownUSN-8620-4: Linux kernel (Intel IoTG) vulnerabilitiesubuntu · 2026-07-31
- unknownUSN-8620-3: Linux kernel (Intel IoTG) vulnerabilitiesubuntu · 2026-07-31
- unknownUSN-8620-2: Linux kernel (Azure FIPS) vulnerabilitiesubuntu · 2026-07-29
- highUSN-8620-1: Linux kernel vulnerabilitiesubuntu · 2026-07-28
- highUSN-8618-1: Linux kernel vulnerabilitiesubuntu · 2026-07-28
- highUSN-8610-1: Linux kernel (Azure CVM) vulnerabilitiesubuntu · 2026-07-24
- highUSN-8575-3: Linux kernel vulnerabilitiesubuntu · 2026-07-24
- highUSN-8603-1: Linux kernel (Azure) vulnerabilitiesubuntu · 2026-07-24
- highUSN-8576-2: Linux kernel (NVIDIA Tegra) vulnerabilitiesubuntu · 2026-07-23
- highUSN-8575-2: Linux kernel vulnerabilitiesubuntu · 2026-07-23
- highUSN-8593-1: Linux kernel vulnerabilitiesubuntu · 2026-07-23
- highUSN-8576-1: Linux kernel (NVIDIA Tegra) vulnerabilitiesubuntu · 2026-07-21
- highUSN-8575-1: Linux kernel vulnerabilitiesubuntu · 2026-07-21
- criticalCVE-2026-64089: In the Linux kernel, the following vulnerability has been resolved: batman-adv: tt: fix negati…nvd · 2026-07-19
External references
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