Unknown

CVE-2026-63902 — USB: serial: cypress_m8: validate interrupt packet headers

In the Linux kernel, the following vulnerability has been resolved: USB: serial: cypress_m8: validate interrupt packet headers cypress_read_int_callback() parses the interrupt-in buffer according to the selected Cypress packet format. Format 1 has a two-byte status/count header and format 2 has a one-byte combined status/count header. The usb-serial core sizes the interrupt-in buffer from the endpoint descriptor's wMaxPacketSize, and successful interrupt transfers can complete short when URB_SHORT_NOT_OK is not set. Check that the completed packet contains the selected header before reading it. Malformed short reports are ignored and the interrupt URB is resubmitted through the existing retry path, preventing out-of-bounds header-byte reads. KASAN report as below: KASAN slab-out-of-bounds in cypress_read_int_callback+0x240/0x7f0 Read of size 1 Call trace: cypress_read_int_callback() (drivers/usb/serial/cypress_m8.c:1009) __usb_hcd_giveback_urb() dummy_timer() [ johan: use constants in header length sanity checks ]

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

0.23%

ahead of 12% 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	≥ 3416eaa1f8f8d516b77de514e14cf8da256d28fb and < fcef31a5a85ccf3c313449a866ec6ed7e4132425≥ 3416eaa1f8f8d516b77de514e14cf8da256d28fb and < aaa66708bfb1dca2acd219d1c1582f9f6d5492cb≥ 3416eaa1f8f8d516b77de514e14cf8da256d28fb and < 44f9bab8df7750a1e2a4d6cc22d7c9c2dc096aed≥ 3416eaa1f8f8d516b77de514e14cf8da256d28fb and < be50533fe7068e86eb7adb81988e6d6a3f6dfe53≥ 3416eaa1f8f8d516b77de514e14cf8da256d28fb and < 90664556916de22467097d4c8ceb716d597a5c32≥ 3416eaa1f8f8d516b77de514e14cf8da256d28fb and < ae03453f2c809ca3cf73753269fa6184dea7160f≥ 3416eaa1f8f8d516b77de514e14cf8da256d28fb and < 4a4cb0021ebe1fcadb52e04d19ed8d71470a530b≥ 3416eaa1f8f8d516b77de514e14cf8da256d28fb and < 9f9bfc80c67f35a275820da7e83a35dface08281 and 1 more version 2.6.26	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/ae03453f2c809ca3cf73753269fa6184dea7160f
NIST National Vulnerability Database
git.kernel.org/stable/c/4a4cb0021ebe1fcadb52e04d19ed8d71470a530b
NIST National Vulnerability Database
git.kernel.org/stable/c/90664556916de22467097d4c8ceb716d597a5c32
NIST National Vulnerability Database
git.kernel.org/stable/c/44f9bab8df7750a1e2a4d6cc22d7c9c2dc096aed
NIST National Vulnerability Database
git.kernel.org/stable/c/aaa66708bfb1dca2acd219d1c1582f9f6d5492cb
NIST National Vulnerability Database
git.kernel.org/stable/c/9f9bfc80c67f35a275820da7e83a35dface08281
NIST National Vulnerability Database
git.kernel.org/stable/c/be50533fe7068e86eb7adb81988e6d6a3f6dfe53
NIST National Vulnerability Database
git.kernel.org/stable/c/fcef31a5a85ccf3c313449a866ec6ed7e4132425
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-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 2d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 2d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 2d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 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-2026-63902 is "USB: serial: cypress_m8: validate interrupt packet headers", 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 0.23% 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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