VulnerabilityPublished 19 May 2026Updated 6 Nov 2026

CVE-2026-43491: Linux kernel · net: qrtr: ns: Limit the maximum server registration per node

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in e6f6cd501fb54060940a6eb3f4103eeb5e426ae7 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 16:04 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, 2026-11-06.

Patch

Available – fixed in e6f6cd501fb54060940a6eb3f4103eeb5e426ae7, d5ee2ff98322337951c56398e79d51815acbf955, b48fc702b20233b809f01053232c3cd5083c97b4 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 19 May 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 6 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 ≥ 0c2204a4ad710d95d348ea006f14ba926e842ffd, < e6f6cd501fb54060940a6eb3f4103eeb5e426ae7	Fixed in e6f6cd501fb54060940a6eb3f4103eeb5e426ae7
LinuxLinux	Affected ≥ 0c2204a4ad710d95d348ea006f14ba926e842ffd, < d5ee2ff98322337951c56398e79d51815acbf955	Fixed in d5ee2ff98322337951c56398e79d51815acbf955
LinuxLinux	Affected ≥ 0c2204a4ad710d95d348ea006f14ba926e842ffd, < b48fc702b20233b809f01053232c3cd5083c97b4	Fixed in b48fc702b20233b809f01053232c3cd5083c97b4
LinuxLinux	Affected ≥ 0c2204a4ad710d95d348ea006f14ba926e842ffd, < 94914731ca0b99899dceadd80d2df00584a688ca	Fixed in 94914731ca0b99899dceadd80d2df00584a688ca
LinuxLinux	Affected ≥ 0c2204a4ad710d95d348ea006f14ba926e842ffd, < 868202aa2adae427060a42d5bd663b4d782ec02c	Fixed in 868202aa2adae427060a42d5bd663b4d782ec02c
LinuxLinux	Affected ≥ 0c2204a4ad710d95d348ea006f14ba926e842ffd, < 991c431077b19176d3fe3bb54054c063776a8cdc	Fixed in 991c431077b19176d3fe3bb54054c063776a8cdc

Description

In the Linux kernel, the following vulnerability has been resolved: net: qrtr: ns: Limit the maximum server registration per node Current code does no bound checking on the number of servers added per node. A malicious client can flood NEW_SERVER messages and exhaust memory. Fix this issue by limiting the maximum number of server registrations to 256 per node. If the NEW_SERVER message is received for an old port, then don't restrict it as it will get replaced. While at it, also rate limit the error messages in the failure path of qrtr_ns_worker(). Note that the limit of 256 is chosen based on the current platform requirements. If requirement changes in the future, this limit can be increased.

References

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