CVE-2026-63387

Description

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an off-by-one stack buffer overflow in evdns.c when dnsname_to_labels formats a name-bearing DNS record at the end of the 64 KB stack buffer allocated by evdns_server_request_format_response. The final-label check permits j plus label_len plus one to equal buf_len, after which the terminating null byte is written to buf[buf_len]. A crafted DNS server response containing PTR, CNAME, MX, NS, or SOA data can trigger the one-byte out-of-bounds write and crash or corrupt the process. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

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Produits concernés

• libevent

Scores CVSS

Faiblesses (CWE)

• CWE-121
• CWE-193
• CWE-787

Références

• https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable
• https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha
• https://github.com/libevent/libevent/security/advisories/GHSA-58rx-7448-jw47
• https://github.com/libevent/libevent/security/advisories/GHSA-58rx-7448-jw47

Ailleurs

• NVD
• CVE.org
• CIRCL Vulnerability-Lookup
• CERT-FR
• GitHub Advisories