Is there a public exploit for CVE-2026-87039?

No public exploit for CVE-2026-87039 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-87039?

CVE-2026-87039 scores CVSS 7.8 (v3.1), rated high.

What does CVE-2026-87039 affect?

CVE-2026-87039 affects zephyrproject Zephyr.

7.8 High

The user-mode syscall verifier zvrfyi2sconfigure() in drivers/i2s/i2shandlers.c copies the caller's struct i2sconfig in from user memory…

CVE-2026-87039

The user-mode syscall verifier zvrfyi2sconfigure() in drivers/i2s/i2shandlers.c copies the caller's struct i2sconfig in from user memory and then, when cfg->frameclkfreq is 0 (the API's "unconfigure the stream" request), jumps straight to zimpli2sconfigure() without performing the KSYSCALLOBJ(config.memslab, KOBJMEMSLAB) ownership/type check or the blocksize sanity check. The memslab field is a struct kmemslab , so on that path a completely unvalidated, user-chosen pointer reaches driver code that is entitled to trust it as a real kernel object. Any thread running under CONFIGUSERSPACE that has access to an I2S device object can trigger this with a single i2sconfigure() call. Most in-tree drivers special-case frameclkfreq == 0 and never store the caller's structure, but drivers/i2s/i2slitex.c does not: i2slitexconfigure() only logs a warning for a mismatched frame clock, then memcpy()s the caller's config into stream->cfg and marks the stream I2SSTATEREADY. A subsequent i2strigger() with I2STRIGGERSTART enables the FIFO interrupt, and the interrupt handlers i2slitexisrrx() / i2slitexisrtx() then call kmemslaballoc() and kmemslabfree() on the attacker-supplied pointer in supervisor…

Assessment

CVSS: 7.8 (v3.1)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 4 November 2026
Last updated: 4 November 2026
Affected: zephyrproject · Zephyr
Assigner: zephyr

CVSS vectorCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

At the source

EUVD (ENISA)

References

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