Cortex-M module ports save a preempted user-mode module thread's registers through its unchecked stack pointer in privileged mode

published 2026-11-02 7 d ago modified 2026-11-02 6 d ago also EUVD-2026-115232

cvss: 7.0; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits: 0; none known

In Eclipse ThreadX versions 6.0.1 through 6.5.2.202603, the PendSV handler of the Cortex-M module ports saves a preempted user-mode module thread's registers in privileged mode at addresses taken from the thread's stack pointer, without checking that pointer against the thread's stack. A user-mode, memory-protected module can thereby write up to nine words, eight of its choosing, or 25 with floating-point state, into memory immediately below any region it may write, and read back what is stored there.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 6 d ago (2026-11-02)

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	7.0	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N
CNA	4.0	7.0	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

Eclipse Foundation Eclipse ThreadX

Classification

Weakness

CWE-787 Out-of-bounds Write
CWE-822 Untrusted Pointer Dereference

References

Sources

CVE List CVE-2026-115653
NVD CVE-2026-115653

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary