Unknown

CVE-2026-90055 — usb: atm: usbatm: fix invalid ci_range initialization

In the Linux kernel, the following vulnerability has been resolved: usb: atm: usbatm: fix invalid ci_range initialization syzbot reported a shift-out-of-bounds in __vcc_connect(): UBSAN: shift-out-of-bounds in net/atm/common.c:382:32 shift exponent -1 is negative CPU: 0 UID: 0 PID: 5987 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Call Trace: <TASK> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233 __ubsan_handle_shift_out_of_bounds+0x36d/0x400 lib/ubsan.c:494 __vcc_connect+0x14b4/0x19c0 net/atm/common.c:382 vcc_connect+0x328/0x8f0 net/atm/common.c:498 pvc_bind+0x272/0x380 net/atm/pvc.c:52 __sys_bind+0x2e3/0x410 net/socket.c:1976 __x64_sys_bind+0x7a/0x90 net/socket.c:1979 ... ATM device ci_range fields (vpi_bits and vci_bits) represent the number of bits supported for VPI and VCI addressing on the device. net/atm/common.c directly uses these fields as bit shift counts: vpi >> dev->ci_range.vpi_bits vci >> dev->ci_range.vci_bits 1 << vcc->dev->ci_range.vpi_bits 1 << vcc->dev->ci_range.vci_bits usbatm_atm_init() sets ci_range.vpi_bits and ci_range.vci_bits to ATM_CI_MAX (-1), which is defined in <uapi/linux/atmdev.h> as a sentinel value for userspace ATM_SETCIRANGE requests, not a valid bit count. Shifting by -1 is undefined behavior and triggers UBSAN warnings. ATM UNI cell headers allow up to 8 bits for VPI (0..255) and 16 bits for VCI (0..65535). Initialize vpi_bits to 8 and vci_bits to 16, as done by solos-pci.

Published Sep 17, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · 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 19, 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	≥ c59bba75fa500f13ef14215d599ee0d7faa1b954 and < 8442586526c406527bf31206e538c0ce6bc672e6≥ c59bba75fa500f13ef14215d599ee0d7faa1b954 and < 561cbd6d49022c9a383e22a39c87a165a4d39f9c≥ c59bba75fa500f13ef14215d599ee0d7faa1b954 and < 76bc7c3a44856744b64aa91d9afe6d9522a78c42≥ c59bba75fa500f13ef14215d599ee0d7faa1b954 and < 7baa0c92be39eb3da755ed6f200497a57078c47b≥ c59bba75fa500f13ef14215d599ee0d7faa1b954 and < 1e964d414bfd9f8dfe9948d08e4b9dda4ed2e422≥ c59bba75fa500f13ef14215d599ee0d7faa1b954 and < ff7f77a234f7b74e5955a6e34fa74eca4c9ca44c≥ c59bba75fa500f13ef14215d599ee0d7faa1b954 and < 75667703115154a4fd9cf259d4f826d8729cbcda≥ c59bba75fa500f13ef14215d599ee0d7faa1b954 and < a60fd8c6dbaa76da4163cf225ed2b9e982540f39 and 1 more version 2.6.13	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 19, 2026 · 4 reading(s) · max 0.21%

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 · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 17, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 19, 2026 – Oct 19, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

10 on the record

git.kernel.org/stable/c/8442586526c406527bf31206e538c0ce6bc672e6
NIST National Vulnerability Database
git.kernel.org/stable/c/561cbd6d49022c9a383e22a39c87a165a4d39f9c
NIST National Vulnerability Database
github.com/advisories/GHSA-vpcj-fg84-6vgj
GitHub Security Advisories
git.kernel.org/stable/c/7baa0c92be39eb3da755ed6f200497a57078c47b
NIST National Vulnerability Database
git.kernel.org/stable/c/76bc7c3a44856744b64aa91d9afe6d9522a78c42
NIST National Vulnerability Database
git.kernel.org/stable/c/ff7f77a234f7b74e5955a6e34fa74eca4c9ca44c
NIST National Vulnerability Database
git.kernel.org/stable/c/75667703115154a4fd9cf259d4f826d8729cbcda
NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-90055
GitHub Security Advisories
git.kernel.org/stable/c/1e964d414bfd9f8dfe9948d08e4b9dda4ed2e422
NIST National Vulnerability Database
git.kernel.org/stable/c/a60fd8c6dbaa76da4163cf225ed2b9e982540f39
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-98866 sched/cache: Introduce task_struct->sched_cache_grp to fix UAF 1d
Unknown CVE-2026-98867 dm-pcache: bound the logical key offset from persistent memory 1d
Unknown CVE-2026-98868 dm-pcache: reject a kset that overruns its segment 1d
Unknown CVE-2026-98856 kprobes: Skip disarmed probes when checking optkprobe overlap 1d
Unknown CVE-2026-98857 ipvs: bound LBLCR and LBLC cache growth 1d
Unknown CVE-2026-98858 io_uring: fix task_work add use-after-free with SQPOLL 1d

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-2026-90055 is "usb: atm: usbatm: fix invalid ci_range initialization", 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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