# CVE-2026-115653: Cortex-M module ports save a preempted user-mode module thread's registers through its unchecked stack pointer in privileged mode

Status: published. Published: 2026-11-02. Updated: 2026-11-02.

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.

## Remediation

- fix: ThreadX (eclipse threadx): GitHub reports patched versions 6.5.2.202603b. Check the advisory for the affected release branch. (source: GitHub GHSA-c38r-v552-gh5g) — https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-c38r-v552-gh5g

## Affected products and versions

- Eclipse Foundation / Eclipse ThreadX: ≥ 6.0.1; ≤ 6.5.2.202603 (affected, custom). Source: CNA: eclipse
-  / ThreadX (ThreadX): >= 6.0.1, <= 6.5.2.202603 (affected, GitHub advisory range). Source: GitHub GHSA-c38r-v552-gh5g

## Severity and prioritization

- CVSS 4.0: 7 (high); 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; source: CNA: eclipse

- CVSS 4.0: 7 (high); 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; source: NVD: emo@eclipse.org

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-787, CWE-822

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-c38r-v552-gh5g (CNA: eclipse)

- https://gitlab.eclipse.org/security/cve-assignment/-/work_items/503 (CNA: eclipse)

- https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-c38r-v552-gh5g (emo@eclipse.org)

- https://gitlab.eclipse.org/security/cve-assignment/-/work_items/503 (emo@eclipse.org)

- https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-c38r-v552-gh5g (GitHub Security Advisories; advisory)

## Provenance

- CNA: eclipse: https://www.cve.org/CVERecord?id=CVE-2026-115653; retrieved 2026-11-02; source updated 2026-11-02

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-115653; retrieved 2026-11-02; source updated 2026-11-02

- GitHub Security Advisories: https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-c38r-v552-gh5g; retrieved 2026-11-02; source updated 2026-11-01

Revision: 9490922748423834e2964d86cd7fedad063d93504275de37f717d58c12ef0ca5

Canonical: https://y2.dev/cve/CVE-2026-115653

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