{"apiVersion":"1.0","identifier":"CVE-2026-62381","description":"luci-lib-px5g (LuCI) contains a heap-based buffer overflow in the native ASN.1 encoding routine asn1_add_obj (x509write.c) when signing a certificate with a 2040-bit RSA key. For a 255-byte signature, the BIT STRING allocation is computed from the DER length encoding of 255 bytes, but the payload written after prepending the unused-bits byte is 256 bytes, requiring one additional DER length octet. As a result the allocation is 259 bytes while the tag, length, unused-bits byte, and signature require 260 bytes, and the final memcpy writes one byte beyond the heap buffer. The overflow is reachable through the exported Lua interface via create_selfsigned(); whether it is remotely exploitable depends on the embedding application. The vulnerable code is present on the openwrt-18.06 through openwrt-25.12 release branches and is absent from master, where the luci-lib-px5g package has been removed rather than patched.","publishedAt":"2026-08-22T13:16:39","lastModifiedAt":"2026-08-24T20:16:53","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-62381","cvssScore":6.6,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H","epssProbability":0.00076,"riskScore":0.66,"affectedProduct":"luci-lib-px5g","affectedVersions":"unknown","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-62381","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-62381","en":"https://www.redsauce.net/en/cves/CVE-2026-62381","fr":"https://www.redsauce.net/fr/cves/CVE-2026-62381","pt":"https://www.redsauce.net/pt/cves/CVE-2026-62381","de":"https://www.redsauce.net/de/cves/CVE-2026-62381","sk":"https://www.redsauce.net/sk/cves/CVE-2026-62381","el":"https://www.redsauce.net/el/cves/CVE-2026-62381"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-62381"}}