VulnerabilityPublished 25 Mar 2026Updated 5 Nov 2026

CVE-2026-23298: Linux kernel · can: ucan: Fix infinite loop from zero-length messages

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in e7bb6e0606b5f233531aaaad9542d69fbb792115 : update Linux kernel when convenient.

Data as of 5 Nov 2026, 22:04 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-05.

Patch

Available – fixed in e7bb6e0606b5f233531aaaad9542d69fbb792115, ca07d3c6eef14d34e6fdeefe55058db045be29dc, c7bc62be6c1a60bb21301692009590b1ffda91d9 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 9f2d3eae88d26c29d96e42983b755940d9169cd9, < e7bb6e0606b5f233531aaaad9542d69fbb792115	Fixed in e7bb6e0606b5f233531aaaad9542d69fbb792115
LinuxLinux	Affected ≥ 9f2d3eae88d26c29d96e42983b755940d9169cd9, < ca07d3c6eef14d34e6fdeefe55058db045be29dc	Fixed in ca07d3c6eef14d34e6fdeefe55058db045be29dc
LinuxLinux	Affected ≥ 9f2d3eae88d26c29d96e42983b755940d9169cd9, < c7bc62be6c1a60bb21301692009590b1ffda91d9	Fixed in c7bc62be6c1a60bb21301692009590b1ffda91d9
LinuxLinux	Affected ≥ 9f2d3eae88d26c29d96e42983b755940d9169cd9, < bd85f21a6219aeae4389d700c54f1799f4b814e0	Fixed in bd85f21a6219aeae4389d700c54f1799f4b814e0
LinuxLinux	Affected ≥ 9f2d3eae88d26c29d96e42983b755940d9169cd9, < ab6f075492d37368b4c7b0df7f7fdc2b666887fc	Fixed in ab6f075492d37368b4c7b0df7f7fdc2b666887fc
LinuxLinux	Affected ≥ 9f2d3eae88d26c29d96e42983b755940d9169cd9, < aa9e0a7fe5efc2f74327fd37d828e9a51d9ff588	Fixed in aa9e0a7fe5efc2f74327fd37d828e9a51d9ff588

Description

In the Linux kernel, the following vulnerability has been resolved: can: ucan: Fix infinite loop from zero-length messages If a broken ucan device gets a message with the message length field set to 0, then the driver will loop for forever in ucan_read_bulk_callback(), hanging the system. If the length is 0, just skip the message and go on to the next one. This has been fixed in the kvaser_usb driver in the past in commit 0c73772cd2b8 ("can: kvaser_usb: leaf: Fix potential infinite loop in command parsers"), so there must be some broken devices out there like this somewhere.

References

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