Affects GNU C Library (glibc), a core OS component used across Linux distros; heap overflow via scanf can cause crash or code execution.
CVE-2026-5450
Heap buffer overflow in glibc scanf %mc with width >1024.
Is CVE-2026-5450 being exploited?
Not confirmed. CVE-2026-5450 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 0.50% probability of exploitation in the next 30 days.
How severe is CVE-2026-5450?
CVE-2026-5450 is rated Critical with a CVSS score of 9.8. 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-2026-5450?
Not known from our data. No patch reference has been recorded for CVE-2026-5450, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-5450 affect?
CVE-2026-5450 affects GNU C Library (glibc) 2.7-2.43, Linux environments using vulnerable glibc. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-5450?
Patch glibc to fixed version when available; monitor for updates.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Heap overflow via scanf %mc with wide >1024 can crash or enable arbitrary code execution on affected hosts.
Patch when possible
- affected>= 2.7 and < *
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.