VulnerabilityPublished 25 Sep 2026Updated 21 Oct 2026

CVE-2026-97939: Linux kernel · ipmr: account multicast table and route memory

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in ec1c6140394ee87127479bc500a3158b125bf07a : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in ec1c6140394ee87127479bc500a3158b125bf07a, d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c, b7ee18725f2292ab554aa96a101ae42d45f008bd +2

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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 ≥ f0ad0860d01e47a3ffd220564c5c653b3afbe962, < ec1c6140394ee87127479bc500a3158b125bf07a	Fixed in ec1c6140394ee87127479bc500a3158b125bf07a
LinuxLinux	Affected ≥ f0ad0860d01e47a3ffd220564c5c653b3afbe962, < d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c	Fixed in d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c
LinuxLinux	Affected ≥ f0ad0860d01e47a3ffd220564c5c653b3afbe962, < b7ee18725f2292ab554aa96a101ae42d45f008bd	Fixed in b7ee18725f2292ab554aa96a101ae42d45f008bd
LinuxLinux	Affected ≥ f0ad0860d01e47a3ffd220564c5c653b3afbe962, < 0264b3ee09b118fec8a5471b4ca288f8ab84722f	Fixed in 0264b3ee09b118fec8a5471b4ca288f8ab84722f
LinuxLinux	Affected ≥ f0ad0860d01e47a3ffd220564c5c653b3afbe962, < 21e0749e8ef272ac7e3eefe0fa488a5983f4b038	Fixed in 21e0749e8ef272ac7e3eefe0fa488a5983f4b038
LinuxLinux	Affected =2.6.35	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: ipmr: account multicast table and route memory A netadmin in a user+net namespace can create many IPv4 and IPv6 multicast routing tables with MRT_TABLE and MRT6_TABLE. Each unseen id allocates an mr_table via the shared mr_table_alloc(), links it into the per-net list, and leaves it until netns teardown. Those objects were not charged to memcg, so the host unreclaimable slab grows with the table count. Account mr_table allocations with GFP_KERNEL_ACCOUNT and mark the IPv4/IPv6 MFC caches SLAB_ACCOUNT. This matches the established handling of IP addresses, routes and alternate interface names. Unresolved MFC entries are still allocated from softIRQ with GFP_ATOMIC and are not charged. They expire after 10 seconds and are bounded by the socket receive queue; see commit 0079ad8e8dc3 ("ipmr: remove hard code cache_resolve_queue_len limit").

References

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