CVE-2026-64271
In the Linux kernel, the following vulnerability has been resolved: Input: touchwin - reset the packet index on every complete packet tw_interrupt() accumulates each non-zero serial byte into a fixed three-byte buffer with a running index that is only…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: Input: touchwin - reset the packet index on every complete packet tw_interrupt() accumulates each non-zero serial byte into a fixed three-byte buffer with a running index that is only reset once a full packet has been received *and* the device's two Y bytes agree: tw->data[tw->idx++] = data; if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) { ... tw->idx = 0; } The reset is gated on tw->data[1] == tw->data[2], a value the device controls. A malicious, malfunctioning or counterfeit Touchwindow peripheral can stream non-zero bytes whose 2nd and 3rd bytes differ: the index reaches TW_LENGTH without the equality holding, is never reset, and keeps growing, so tw->data[tw->idx++] walks off the end of the three-byte array and the rest of the heap-allocated struct tw, one attacker-chosen byte at a time -- an unbounded, device-driven heap out-of-bounds write. Reset the index on every completed packet and report an event only when the two Y bytes match, like the other serio touchscreen drivers do.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.17% probability · 6th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-129
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/044167cba2384bcd783547ad5e30ecd292b30919Patch
- https://git.kernel.org/stable/c/3e6f007b43e2fc6546e21fa74ee62c38984a6672Patch
- https://git.kernel.org/stable/c/431ad239f2924dff337c3fccb9246597c1b63185Patch
- https://git.kernel.org/stable/c/478cdd736f2ce3114f90e775d7358136d3977b94Patch
- https://git.kernel.org/stable/c/6c9f29f128dd4057404838259af4c645318487e1Patch
- https://git.kernel.org/stable/c/70e4248793762df9832fd4fc2fc6ac7924572c36Patch
- https://git.kernel.org/stable/c/a8d87184576c889759e3aab899799a482f1e1a5bPatch
- https://git.kernel.org/stable/c/ed9b66905407eb3d02df1aaeed82eb7a7f0eb508Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.