{"apiVersion":"1.0","identifier":"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.","publishedAt":"2026-08-20T18:16:36","lastModifiedAt":"2026-08-25T16:17:05","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63387","cvssScore":7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","epssProbability":0.00345,"riskScore":0.72,"affectedProduct":"libevent","affectedVersions":"<2.1.13, <2.2.2-alpha","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-63387","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-63387","en":"https://www.redsauce.net/en/cves/CVE-2026-63387","fr":"https://www.redsauce.net/fr/cves/CVE-2026-63387","pt":"https://www.redsauce.net/pt/cves/CVE-2026-63387","de":"https://www.redsauce.net/de/cves/CVE-2026-63387","sk":"https://www.redsauce.net/sk/cves/CVE-2026-63387","el":"https://www.redsauce.net/el/cves/CVE-2026-63387"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-63387"}}