CVE-2026-63626

8.8 HIGH 0.2% exploit odds Fix listed Memory safety Device

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.

At a glance

Exploitability: Can be exploited from the same network segment without logging in. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-07-17 14:11 UTC ReservedThe CVE id was reserved by its CNA
2026-10-14 19:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-16 20:04 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.2% in the next 30 days (EPSS).
Severity: 8.8 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-10-14 19:17 UTC
Last modified: 2026-10-16 20:04 UTC
Exploit probability: 0.2% · EPSS, next 30 days
Weakness: CWE-122
Record status: Deferred

Attack profile CVSS 3.1 · 8.8

Attack vector: Adjacent network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2026-63626.md and follow it. Check whether this project is affected by CVE-2026-63626. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record