CVE-2026-63964
N/AIn the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: ccg: reject firmware images without a ':' record header do_flash() locates the first .cyacd record with p = strnchr(fw->data, fw->size, ':'); while (p < eof) { s = strnchr(p + 1, eof - p - 1, ':'); ... } If the firmware image contains no ':' byte, strnchr() returns NULL. NULL compares less than the valid kernel pointer eof, so the loop body runs and strnchr() is called with p + 1 == (void *)1 and a length of roughly (unsigned long)eof, causing a wonderful crash. The not_signed_fw fallthrough earlier in do_flash() and the chip-state branches in ccg_fw_update_needed() allow an unsigned blob to reach this loop, so a root user who can place a crafted file under /lib/firmware and write the do_flash sysfs attribute can trigger the oops. Bail out with -EINVAL when the initial strnchr() returns NULL.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 11th percentile
Impact if exploited
—CVSS · not scored
- No impact metrics
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-63964/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-63964/poc.json
References
Technical & other
- https://git.kernel.org/stable/c/b41dfc033fe594e152648050e95b9489cd53e9e3
- https://git.kernel.org/stable/c/2f395ca1263bd181995eb829f5943a83a20db213
- https://git.kernel.org/stable/c/6526f8684f72391138353642af908803ba70795e
- https://git.kernel.org/stable/c/3f432b8203066c26770fe6ea591361f10021dd6b
- https://git.kernel.org/stable/c/c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb
- https://git.kernel.org/stable/c/a38ed87818b2419090fb1a6338ddce6842b65dfa
- https://git.kernel.org/stable/c/c8460de584fe5415d212cfdd127d4db90835a450
- https://git.kernel.org/stable/c/d7486952bf74e546ee3748fb14b2d07881fa6273