CVE-2026-63626CWE-122CWE-125

CVE-2026-63626

High · published October 14, 2026

CVSS v3.1
8.8
EPSS
0%
Percentile
14.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00239 · 14.2th percentile
Weaknesses
CWE-122 · Heap-based Buffer Overflow; CWE-125 · Out-of-bounds Read
Published
2026-10-14T23:17Z
References (3)
https://github.com/cesanta/mongoose/commit/751f14742dea934bec08a507ab1fecc3673d4903 · [email protected]https://github.com/cesanta/mongoose/releases/tag/7.23 · [email protected]https://github.com/cesanta/mongoose/security/advisories/GHSA-pc66-j6r6-49x9 · [email protected]
EPSS history
Timeline
  • 16 OCT 03:31Z
    EPSS moved — → 0%
    epss
  • 14 OCT 18:26Z
    Mongoose: ppp_handle_ipv6cp() uses attacker-controlled length without bounds check — OOB read and heap overflow (PPP/PPPoE, MG_ENABLE_IPV6)
    cvelistv5
  • 14 OCT 18:26Z
    Mongoose: ppp_handle_ipv6cp() uses attacker-controlled length without bounds check — OOB read and heap overflow (PPP/PPPoE, MG_ENABLE_IPV6)
    cvelistv5