In the Linux kernel, the following vulnerability has been resolved: ALSA: firewire: isight: bound the sample count to the packet payload… (CVE-2026-64483)
Source GCVE Database
No CVSS score published yet
- Exploitation
Not in CISA KEV, no exploitation reported
- 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.
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
- nvd.nist.gov/vuln/detail/CVE-2026-64483 (opens in a new tab)
- git.kernel.org/stable/c/24423e0a9251d348c3f1fb0bb0e61b879e1e976c (opens in a new tab)
- git.kernel.org/stable/c/29b9667982e4df2ed7744f86b1144f8bb58eb698 (opens in a new tab)
- git.kernel.org/stable/c/31a01b70bb90e3ef3147f308e2ea899e1d2485ca (opens in a new tab)
- git.kernel.org/stable/c/31da82b9676c6b112e7c72c7529e6812b919742a (opens in a new tab)
- git.kernel.org/stable/c/3ed2fa1ed8cc65f910b8bbc0be3cc366b30f8478 (opens in a new tab)
- git.kernel.org/stable/c/57e4d9043afc1eaddee8f50d11def6e65415d273 (opens in a new tab)
- git.kernel.org/stable/c/8e48a29813df8dd71503800b7acf69c12c035045 (opens in a new tab)
- git.kernel.org/stable/c/ebbffacda6733dcbcef601b5b523460f8d8b671e (opens in a new tab)