Vulnerability Intelligence Report
scanf %mc off-by-one heap buffer overflow
CVE-2026-5450
Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.
No Active Exploit Signals
CVSS Base Score
9.8
CRITICAL
Exploitability:3.9
Impact Score:5.9
EPSS Probability:0.45%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
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SSVC Action
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Weaknesses (CWE)
CWE-122 ↗CWE-122 Heap-based buffer overflow
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| The GNU C Library | glibc | 2.7 < * (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
EPSS Score
0.451%
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | GNU C Library · Open Source · USA |
| Reserved | 2026-04-02T21:47:21 |
| Published | 2026-04-20T20:55:41 |
| Patch Date | 2026-03-19 |
| Last Updated | 2026-07-14T12:45:30 |
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