Affects widely used musl libc across Linux distros/containers; memory corruption in qsort on large arrays could impact many systems.
CVE-2026-40200
Stack-based memory corruption in musl libc qsort on very large arrays.
Is CVE-2026-40200 being exploited?
Not confirmed. CVE-2026-40200 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.17% probability of exploitation in the next 30 days.
How severe is CVE-2026-40200?
CVE-2026-40200 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-40200?
Yes. A fix has been recorded for CVE-2026-40200. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-40200 affect?
CVE-2026-40200 affects musl libc 0.7.10-1.2.6. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-40200?
Update to latest musl libc (>=1.2.7) and recompile.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Memory corruption during qsort on huge arrays; may crash or allow arbitrary code execution.
Patch when possible
- affected>= 0.7.10 and <= 1.2.6
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.