CVE-2026-63626
Mongoose: ppp_handle_ipv6cp() uses attacker-controlled length without bounds check — OOB read and heap overflow (PPP/PPPoE, MG_ENABLE_IPV6)
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.
| CWE | CWE-122 CWE-125 |
| Vendor | cesanta |
| Product | mongoose |
| Published | Oct 14, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H