VulnerabilityPublished 25 Jul 2026

CVE-2026-64483: Linux kernel · ALSA: firewire: isight: bound the sample count to the packet payload

Source GCVE Database

Not known to be exploited.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Medium

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-j22x-mh97-frw2

What to do

AI-suggested

A fix has been implemented in the Linux kernel to bound the sample count to MAX_FRAMES_PER_PACKET, preventing out-of-bounds memory access. Users should update to a Linux kernel version that includes this fix once available.

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: firewire: isight: bound the sample count to the packet payload isight_packet() takes the frame count from the device iso packet and checks it only against the device claimed iso length. count = be32_to_cpu(payload->sample_count); if (likely(count <= (length - 16) / 4)) isight_samples(isight, payload->samples, count); length is the iso header data_length. It can be up to 0xffff. So the gate allows a count up to about 16379. isight_samples() then copies count frames out of payload->samples into the PCM DMA buffer. payload->samples holds only 2 * MAX_FRAMES_PER_PACKET values. The device multiplexes two samples per frame. A count past MAX_FRAMES_PER_PACKET reads past the payload. A count past the buffer size writes past runtime->dma_area. The smallest PCM buffer is larger than MAX_FRAMES_PER_PACKET. Bounding the count to MAX_FRAMES_PER_PACKET keeps both the read and the write in range. A malicious or faulty Apple iSight on the FireWire bus reaches this during a normal capture. Add the MAX_FRAMES_PER_PACKET bound to the gate.

Impact

An attacker controlling a malicious or faulty Apple iSight device connected via FireWire could cause out-of-bounds memory reads and writes in the ALSA isight driver during normal audio capture. This could potentially lead to memory corruption or system instability. No known exploits in the wild have been reported.

Summary

The Linux kernel ALSA firewire isight driver function isight_packet() took the sample count from the device iso packet and only checked it against the device's claimed iso length, which could be up to 0xffff. This allowed a sample count up to about 16379, while the payload samples buffer only held 2 * MAX_FRAMES_PER_PACKET values. Consequently, a sample count exceeding MAX_FRAMES_PER_PACKET could cause out-of-bounds reads from the payload and out-of-bounds writes to the PCM DMA buffer. The vulnerability could be triggered by a malicious or faulty Apple iSight device on the FireWire bus during normal capture. The fix added a bound on the sample count to MAX_FRAMES_PER_PACKET, preventing these out-of-bounds operations.

References

Community reviews

Loading reviews…