Vulnerability · Published Aug 24, 2026 · Assigned by VulDB
CVE-2026-78161warmcat libwebsockets LECP CBOR Recording lecp.c report_raw_cbor out-of-bounds write
High 7.3
In plain English
A high-severity out-of-bounds write in libwebsockets from warmcat. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
A vulnerability was found in warmcat libwebsockets 4.5.0. Impacted is the function report_raw_cbor of the file lib/misc/lecp.c of the component LECP CBOR Recording. The manipulation results in out-of-bounds write. The attack can be launched remotely. The exploit has been made public and could be used. The patch is identified as 1d44554a1bb262db63ff4e240152a9deecd99054. It is best practice to apply a patch to resolve this issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | libwebsockets | 4.3.5-1+deb13u2 | DEBIAN-CVE-2026-78161 |
| Debian:14 | libwebsockets | 4.3.5-6 | DEBIAN-CVE-2026-78161 |
| Ubuntu:26.04:LTS | libwebsockets | 4.3.5-3ubuntu1.1 | UBUNTU-CVE-2026-78161 |
| Ubuntu:26.04:LTS | libwebsockets | 4.3.5-3ubuntu1.1 | USN-8822-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| warmcat | libwebsockets | 4.5.0 |
Weakness: CWE-787, CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
References
- VDB-394543 | warmcat libwebsockets LECP CBOR Recording lecp.c report_raw_cbor out-of-bounds write vdb-entry, technical-description
- VDB-394543 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- CVE-2026-78161 | CVE Analysis and Report third-party-advisory
- Submit #883225 | warmcat libwebsockets 4.5.99-v4.5.0-508-gb4b5aed39 Out-of-bounds Write third-party-advisory
- https://github.com/biniamf/pocs/tree/main/libwebsockets-lecp-lecp_parse-cbor_pos_oob_write exploit
- https://github.com/biniamf/pocs/blob/main/libwebsockets-lecp-lecp_parse-cbor_pos_oob_write/poc_lecp_cbor_pos_oob.c exploit
- https://github.com/warmcat/libwebsockets/commit/1d44554a1bb262db63ff4e240152a9deecd99054 patch
- https://github.com/warmcat/libwebsockets/ product