PatchTheCVECVE-2026-5772: A 1-byte stack buffer over-read was identified in the MatchDomainName function (src/internal.c) during wildcar
CVE-2026-5772 is a medium-severity flaw (CVSS 5.3) affecting wolfssl. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
A 1-byte stack buffer over-read was identified in the MatchDomainName function (src/internal.c) during wildcard hostname validation when the LEFT_MOST_WILDCARD_ONLY flag is active. If a wildcard * exhausts the entire hostname string, the function reads one byte past the buffer without a bounds check, which could cause a crash.
Why this priority
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.3 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.2% (top 87%) |
| CISA exploited list | No |
| Weakness | CWE-126 |
| Published | 2026-04-09 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-5772?
wolfssl: upgrade to 5.9.1. Exact commands for each OS are on this page.
Is CVE-2026-5772 being exploited?
CVE-2026-5772 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-5772 affect?
CVE-2026-5772 affects wolfssl. Severity is medium (CVSS 5.3). A 1-byte stack buffer over-read was identified in the MatchDomainName function (src/internal.c) during wildcard hostname validation when the LEFT_MOST_WILDCARD_ONLY flag is active. If a wildcard * exhausts the entire hostname string, the f
How urgent is CVE-2026-5772?
Priority 27/100. Remotely exploitable, no login, no user action
Software pages
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