How severe is CVE-2025-5866?

CVE-2025-5866 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-5866 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-5866?

CVE-2025-5866 affects Rt-thread. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-5866?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-5866 have an EU (EUVD) identifier?

Yes. CVE-2025-5866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-17438.

When was CVE-2025-5866 published?

CVE-2025-5866 was published on 2025-06-09 and last updated on 2026-06-17.

CVE-2025-5866

CVE-2025-5866 is a high-severity vulnerability in Rt-thread with a CVSS 3.x base score of 8.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-129.

Key facts

Severity: High (CVSS 3.x base score 8.0)
CVSS v2: 7.4
CVSS v4: 8.6
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-17438
Weakness: CWE-129
Affected product: Rt-thread
Published: 2025-06-09
Last modified: 2026-06-17

Description

A vulnerability classified as critical has been found in RT-Thread 5.1.0. This affects the function sys_sigprocmask of the file rt-thread/components/lwp/lwp_syscall.c. The manipulation of the argument how leads to improper validation of array index.

Frequently asked questions

What is CVE-2025-5866?: A vulnerability classified as critical has been found in RT-Thread 5.1.0. This affects the function sys_sigprocmask of the file rt-thread/components/lwp/lwp_syscall.c. The manipulation of the argument how leads to improper validation of array index.
How severe is CVE-2025-5866?: CVE-2025-5866 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-5866 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-5866?: CVE-2025-5866 affects Rt-thread. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-5866?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-5866 have an EU (EUVD) identifier?: Yes. CVE-2025-5866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-17438.
When was CVE-2025-5866 published?: CVE-2025-5866 was published on 2025-06-09 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:rt-thread:rt-thread:5.1.0:*:*:*:*:*:*:*

More vulnerabilities in Rt-thread

CVE-2024-25393 — Critical (CVSS 9.8): A stack buffer overflow occurs in net/at/src/at_server.c in RT-Thread through 5.0.2.
CVE-2024-25395 — High (CVSS 8.8): A buffer overflow occurs in utilities/rt-link/src/rtlink.c in RT-Thread through 5.0.2.
CVE-2024-25391 — High (CVSS 8.4): A stack buffer overflow occurs in libc/posix/ipc/mqueue.c in RT-Thread through 5.0.2.
CVE-2024-25390 — High (CVSS 8.4): A heap buffer overflow occurs in finsh/msh_file.c and finsh/msh.c in RT-Thread through 5.0.2.
CVE-2024-25388 — High (CVSS 8.4): drivers/wlan/wlan_mgmt,c in RT-Thread through 5.0.2 has an integer signedness error and resultant buffer overflow.
CVE-2024-24335 — High (CVSS 8.4): A heap buffer overflow occurs in the dfs_v2 romfs filesystem RT-Thread through 5.0.2.

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Other CWE-129 (Improper Validation of Array Index) vulnerabilities

CVE-2020-27485 — Critical (CVSS 9.9): Garmin Forerunner 235 before 8.20 is affected by: Array index error. The component is: ConnectIQ TVM. The attack vector…
CVE-2020-27483 — Critical (CVSS 9.9): Garmin Forerunner 235 before 8.20 is affected by: Array index error. The component is: ConnectIQ TVM. The attack vector…
CVE-2026-21413 — Critical (CVSS 9.8): A heap-based buffer overflow vulnerability exists in the lossless_jpeg_load_raw functionality of LibRaw Commit 0b56545…
CVE-2025-27034 — Critical (CVSS 9.8): Memory corruption while selecting the PLMN from SOR failed list.
CVE-2025-3357 — Critical (CVSS 9.8): IBM Tivoli Monitoring 6.3.0.7 through 6.3.0.7 Service Pack 19 could allow a remote attacker to execute arbitrary code…
CVE-2024-45569 — Critical (CVSS 9.8): Memory corruption while parsing the ML IE due to invalid frame content.

Browse all CWE-129 (Improper Validation of Array Index) vulnerabilities →