CVE-2026-40200
CVE-2026-40200 is a high-severity vulnerability with a CVSS 3.x base score of 8.1. 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-670.
Key facts
- Severity: High (CVSS 3.x base score 8.1)
- EPSS exploit prediction: 0% (3rd percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-21496
- Weakness: CWE-670
- Published:
- Last modified:
Description
An issue was discovered in musl libc 0.7.10 through 1.2.6. Stack-based memory corruption can occur during qsort of very large arrays, due to incorrectly implemented double-word primitives. The number of elements must exceed about seven million, i.e., the 32nd Leonardo number on 32-bit platforms (or the 64th Leonardo number on 64-bit platforms, which is not practical).
Frequently asked questions
- What is CVE-2026-40200?
- An issue was discovered in musl libc 0.7.10 through 1.2.6. Stack-based memory corruption can occur during qsort of very large arrays, due to incorrectly implemented double-word primitives. The number of elements must exceed about seven million, i.e., the 32nd Leonardo number on 32-bit platforms (or the 64th Leonardo number on 64-bit platforms, which is not practical).
- How severe is CVE-2026-40200?
- CVE-2026-40200 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2026-40200 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-40200?
- 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-2026-40200 have an EU (EUVD) identifier?
- Yes. CVE-2026-40200 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21496.
- When was CVE-2026-40200 published?
- CVE-2026-40200 was published on 2026-04-10 and last updated on 2026-06-17.
References
- https://musl.libc.org/releases.html
- https://www.openwall.com/lists/oss-security/2026/04/10/13
- http://www.openwall.com/lists/oss-security/2026/04/10/13
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