VulnerabilityPublished 14 Feb 2026Updated 5 Nov 2026

CVE-2026-23140: Linux kernel · bpf, test_run: Subtract size of xdp_frame from allowed metadata size

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in e7440935063949d6f2c10f7328d960d0ff4bce90 : update Linux kernel when convenient.

Data as of 5 Nov 2026, 23:24 UTC

Severity

Unrated

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

Thin evidence

One scorer or none

EPSS

0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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 e7440935063949d6f2c10f7328d960d0ff4bce90, e558cca217790286e799a8baacd1610bda31b261, 6447e697cfa8a43a8e491cb81bcc390d0f28f8ba +2

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Feb 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 ≥ b6f1f780b3932ae497ed85e79bc8a1e513883624, < e7440935063949d6f2c10f7328d960d0ff4bce90	Fixed in e7440935063949d6f2c10f7328d960d0ff4bce90
LinuxLinux	Affected ≥ b6f1f780b3932ae497ed85e79bc8a1e513883624, < e558cca217790286e799a8baacd1610bda31b261	Fixed in e558cca217790286e799a8baacd1610bda31b261
LinuxLinux	Affected ≥ b6f1f780b3932ae497ed85e79bc8a1e513883624, < 6447e697cfa8a43a8e491cb81bcc390d0f28f8ba	Fixed in 6447e697cfa8a43a8e491cb81bcc390d0f28f8ba
LinuxLinux	Affected ≥ b6f1f780b3932ae497ed85e79bc8a1e513883624, < 31e37f44b60679d90b9f999c91371b15291be8e0	Fixed in 31e37f44b60679d90b9f999c91371b15291be8e0
LinuxLinux	Affected ≥ b6f1f780b3932ae497ed85e79bc8a1e513883624, < 7c81ad5e580bd8441f8a521a8d34824ce6582ae5	Fixed in 7c81ad5e580bd8441f8a521a8d34824ce6582ae5
LinuxLinux	Affected =5.18	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: bpf, test_run: Subtract size of xdp_frame from allowed metadata size The xdp_frame structure takes up part of the XDP frame headroom, limiting the size of the metadata. However, in bpf_test_run, we don't take this into account, which makes it possible for userspace to supply a metadata size that is too large (taking up the entire headroom). If userspace supplies such a large metadata size in live packet mode, the xdp_update_frame_from_buff() call in xdp_test_run_init_page() call will fail, after which packet transmission proceeds with an uninitialised frame structure, leading to the usual Bad Stuff. The commit in the Fixes tag fixed a related bug where the second check in xdp_update_frame_from_buff() could fail, but did not add any additional constraints on the metadata size. Complete the fix by adding an additional check on the metadata size. Reorder the checks slightly to make the logic clearer and add a comment.

References

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