CVE-2026-64055
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: cortina: Carry over frag counter
The gmac_rx() NAPI poll function assembles packets in an
SKB from a ring buffer.
If the ring buffer gets completely emptied during a poll cycle,
we exit gmac_rx(), but the packet is not yet completely
assembled in the SKB, yet the fragment counter frag_nr is
reset to zero on the next invocation.
Solve this by making the RX fragment counter a part of the
port struct, and carry it over between invocations.
Reset the fragment counter only right after calling
napi_gro_frags(), on error (after calling napi_free_frags())
or if stopping the port.
Reset it in some place where not strictly necessary just to
emphasize what is going on.
This was found by Sashiko during normal patch review.
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 risk0.51% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 42% 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-2026-64055: In the Linux kernel, the following vulnerability has been resolved: net: ethernet: cortina: Ca…nvd · 2026-07-19
External references
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