Unknown

CVE-2026-63964 — usb: typec: ucsi: ccg: reject firmware images without a ':' record header

In 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.

Published Jul 19, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+2

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.21%

ahead of 11% of scored CVEs · Oct 15, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 and < b41dfc033fe594e152648050e95b9489cd53e9e3≥ 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 and < 2f395ca1263bd181995eb829f5943a83a20db213≥ 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 and < 6526f8684f72391138353642af908803ba70795e≥ 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 and < 3f432b8203066c26770fe6ea591361f10021dd6b≥ 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 and < c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb≥ 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 and < a38ed87818b2419090fb1a6338ddce6842b65dfa≥ 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 and < c8460de584fe5415d212cfdd127d4db90835a450≥ 5c9ae5a87573d38cfc4c740aafda2fa6ce06e401 and < d7486952bf74e546ee3748fb14b2d07881fa6273 and 1 more version 5.2	Vulnerable	CVE Program (cve.org) e CISA ADP

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Awaiting Analysis
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Jul 19, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

git.kernel.org/stable/c/2f395ca1263bd181995eb829f5943a83a20db213
NIST National Vulnerability Database
git.kernel.org/stable/c/b41dfc033fe594e152648050e95b9489cd53e9e3
NIST National Vulnerability Database
git.kernel.org/stable/c/a38ed87818b2419090fb1a6338ddce6842b65dfa
NIST National Vulnerability Database
git.kernel.org/stable/c/d7486952bf74e546ee3748fb14b2d07881fa6273
NIST National Vulnerability Database
git.kernel.org/stable/c/3f432b8203066c26770fe6ea591361f10021dd6b
NIST National Vulnerability Database
git.kernel.org/stable/c/6526f8684f72391138353642af908803ba70795e
NIST National Vulnerability Database
git.kernel.org/stable/c/c8460de584fe5415d212cfdd127d4db90835a450
NIST National Vulnerability Database
git.kernel.org/stable/c/c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 1d
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 2d
Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 2d
Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 2d
Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 2d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-63964 is "usb: typec: ucsi: ccg: reject firmware images without a ':' record header", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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