CVE-2026-64487
In the Linux kernel, the following vulnerability has been resolved:
ALSA: caiaq: fix out-of-bounds read in the Traktor Kontrol S4 input parser
snd_usb_caiaq_tks4_dispatch() decodes the Traktor Kontrol S4 input
stream in fixed 16-byte (TKS4_MSGBLOCK_SIZE) message blocks. On every
iteration it advances buf and subtracts the block size while looping on
"while (len)".
len is urb->actual_length. That value is supplied by the device and is
not guaranteed to be a multiple of 16. When a final short block leaves
len between 1 and 15, the loop runs once more, reads up to buf[15], and
then does "len -= TKS4_MSGBLOCK_SIZE". As len is unsigned this underflows
to a huge value. The loop then keeps iterating and walking buf far past
the end of the 512-byte ep4_in_buf, reading out of bounds until a bogus
block id happens to be hit.
Iterate only while a full message block is available. This stops the
unsigned underflow and silently drops any trailing partial block, which
carries no complete control value anyway.
The sibling endpoint-4 parsers are not affected. The Traktor Kontrol X1
and Maschine arms in snd_usb_caiaq_ep4_reply_dispatch() floor
urb->actual_length before dispatching.
CSIRTS triage
- What
- A vulnerability in ALSA allows for an out-of-bounds read in the Traktor Kontrol S4 input parser.
- Who is affected
- Users of ALSA with the affected input parser.
- Urgency
- Remediation is medium urgency as it could lead to potential exploitation.
- Action
- Apply the latest patches for ALSA to fix this issue.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.18% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 8% of all EPSS-scored CVEs.
Advisory coverage (2)
External references
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