VulnerabilityPublished 24 Jun 2026Updated 6 Nov 2026

CVE-2026-52925: Linux kernel · vrf: Fix a potential NPD when removing a port from a VRF

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in d47204c127992da0c976ac9747070a575912e0fe : update Linux kernel when convenient.

Data as of 6 Nov 2026, 16:49 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 d47204c127992da0c976ac9747070a575912e0fe, a7a97f2303e63ede105c1d55ef53dc497364e11d, 2674d603a9e6970463b2b9ebcf8e31e90beae169 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Jun 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 ≥ fdeea7be88b12742bfd50d9e19a06c0d2e702400, < d47204c127992da0c976ac9747070a575912e0fe	Fixed in d47204c127992da0c976ac9747070a575912e0fe
LinuxLinux	Affected ≥ fdeea7be88b12742bfd50d9e19a06c0d2e702400, < a7a97f2303e63ede105c1d55ef53dc497364e11d	Fixed in a7a97f2303e63ede105c1d55ef53dc497364e11d
LinuxLinux	Affected ≥ fdeea7be88b12742bfd50d9e19a06c0d2e702400, < 2674d603a9e6970463b2b9ebcf8e31e90beae169	Fixed in 2674d603a9e6970463b2b9ebcf8e31e90beae169
LinuxLinux	Affected ≥ fdeea7be88b12742bfd50d9e19a06c0d2e702400, < 468defa0b70902a22f4478c1207624bc1b31c124	Fixed in 468defa0b70902a22f4478c1207624bc1b31c124
LinuxLinux	Affected ≥ fdeea7be88b12742bfd50d9e19a06c0d2e702400, < 8c2b792f04a3db97c9d8d2a45817e93f8884baf5	Fixed in 8c2b792f04a3db97c9d8d2a45817e93f8884baf5
LinuxLinux	Affected ≥ fdeea7be88b12742bfd50d9e19a06c0d2e702400, < 4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4	Fixed in 4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4

Description

In the Linux kernel, the following vulnerability has been resolved: vrf: Fix a potential NPD when removing a port from a VRF RCU readers that identified a net device as a VRF port using netif_is_l3_slave() assume that a subsequent call to netdev_master_upper_dev_get_rcu() will return a VRF device. They then continue to dereference its l3mdev operations. This assumption is not always correct and can result in a NPD [1]. There is no RCU synchronization when removing a port from a VRF, so it is possible for an RCU reader to see a new master device (e.g., a bridge) that does not have l3mdev operations. Fix by adding RCU synchronization after clearing the IFF_L3MDEV_SLAVE flag. Skip this synchronization when a net device is removed from a VRF as part of its deletion and when the VRF device itself is deleted. In the latter case an RCU grace period will pass by the time RTNL is released. [1] BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] RIP: 0010:l3mdev_fib_table_rcu (net/l3mdev/l3mdev.c:181) [...] Call Trace: <TASK> l3mdev_fib_table_by_index (net/l3mdev/l3mdev.c:201 net/l3mdev/l3mdev.c:189) __inet_bind (net/ipv4/af_inet.c:499 (discriminator 3)) inet_bind_sk (net/ipv4/af_inet.c:469) __sys_bind (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:1951 (discriminator 1)) __x64_sys_bind (net/socket.c:1969 (discriminator 1) net/socket.c:1967 (discriminator 1) net/socket.c:1967 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

References

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