{"id":"CVE-2026-63626","summary":"Mongoose: ppp_handle_ipv6cp() uses attacker-controlled length without bounds check — OOB read and heap overflow (PPP/PPPoE, MG_ENABLE_IPV6)","details":"Mongoose is an embedded web server and network library. Prior to 7.23, ppp_handle_ipv6cp() in src/l2_ppp.c trusts the 16-bit IPv6CP len field without checking it against the received payload size. On a PPP or PPPoE link using MG_ENABLE_TCPIP and MG_ENABLE_IPV6, an unauthenticated adjacent peer can complete the required LCP exchange and send a short Configure-Request with an oversized length, causing ppp_tx_frame() to read beyond recv_queue.buf and write beyond tx.buf. The same length misuse can also expose adjacent heap bytes in a reply or hang the event loop through find_opt(). This issue is fixed in version 7.23.","aliases":["GHSA-pc66-j6r6-49x9"],"modified":"2026-10-15T10:47:31.566020451Z","published":"2026-10-14T18:26:16.830Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63626.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-122","CWE-125"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63626.json"},{"type":"FIX","url":"https://github.com/cesanta/mongoose/commit/751f14742dea934bec08a507ab1fecc3673d4903"},{"type":"WEB","url":"https://github.com/cesanta/mongoose/releases/tag/7.23"},{"type":"ADVISORY","url":"https://github.com/cesanta/mongoose/security/advisories/GHSA-pc66-j6r6-49x9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63626"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/cesanta/mongoose","events":[{"introduced":"0"},{"fixed":"02bdbb9ed6f0a8f7c42228c6e7cb35d748b60551"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"7.23"}],"source":"AFFECTED_FIELD"}}],"versions":["7.22","7.21","7.20","7.19","7.18","7.17","7.16","7.15","7.14","7.13","7.12","7.11","7.8","7.7","7.6","7.5","7.4","7.3","7.2","7.1","7.0","6.18","6.17","6.16","6.15","6.14","6.13","6.12","6.11","6.10","6.9","6.7","6.6","6.5","6.4","6.3","6.2","6.1","6.0","5.6","5.5_20140120","5.5","5.4","5.3","5.2","5.1","5.0","4.1","4.0","3.8","3.7","3.6","3.5","3.4","3.3","3.2"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63626.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}