VulnerabilityPublished 25 Mar 2026Updated 5 Nov 2026

CVE-2026-23359: Linux kernel · bpf: Fix stack-out-of-bounds write in devmap

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in d2c31d8e03d05edc16656e5ffe187f0d1da763d7 : 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 d2c31d8e03d05edc16656e5ffe187f0d1da763d7, ca831567908fd3f73cf97d8a6c09a5054697a182, b7bf516c3ecd9a2aae2dc2635178ab87b734fef1 +4

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 ≥ aeea1b86f9363f3feabb496534d886f082a89f21, < d2c31d8e03d05edc16656e5ffe187f0d1da763d7	Fixed in d2c31d8e03d05edc16656e5ffe187f0d1da763d7
LinuxLinux	Affected ≥ aeea1b86f9363f3feabb496534d886f082a89f21, < ca831567908fd3f73cf97d8a6c09a5054697a182	Fixed in ca831567908fd3f73cf97d8a6c09a5054697a182
LinuxLinux	Affected ≥ aeea1b86f9363f3feabb496534d886f082a89f21, < b7bf516c3ecd9a2aae2dc2635178ab87b734fef1	Fixed in b7bf516c3ecd9a2aae2dc2635178ab87b734fef1
LinuxLinux	Affected ≥ aeea1b86f9363f3feabb496534d886f082a89f21, < 5000e40acc8d0c36ab709662e32120986ac22e7e	Fixed in 5000e40acc8d0c36ab709662e32120986ac22e7e
LinuxLinux	Affected ≥ aeea1b86f9363f3feabb496534d886f082a89f21, < 88df604f0d16a692867582350ce3f2fcd22243f1	Fixed in 88df604f0d16a692867582350ce3f2fcd22243f1
LinuxLinux	Affected ≥ aeea1b86f9363f3feabb496534d886f082a89f21, < 75d474702b2ba8b6bcb26eb3004dbc5e95ffd5d2	Fixed in 75d474702b2ba8b6bcb26eb3004dbc5e95ffd5d2

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix stack-out-of-bounds write in devmap get_upper_ifindexes() iterates over all upper devices and writes their indices into an array without checking bounds. Also the callers assume that the max number of upper devices is MAX_NEST_DEV and allocate excluded_devices[1+MAX_NEST_DEV] on the stack, but that assumption is not correct and the number of upper devices could be larger than MAX_NEST_DEV (e.g., many macvlans), causing a stack-out-of-bounds write. Add a max parameter to get_upper_ifindexes() to avoid the issue. When there are too many upper devices, return -EOVERFLOW and abort the redirect. To reproduce, create more than MAX_NEST_DEV(8) macvlans on a device with an XDP program attached using BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS. Then send a packet to the device to trigger the XDP redirect path.

References

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