CVE-2026-78161warmcat libwebsockets LECP CBOR Recording lecp.c report_raw_cbor out-of-bounds write
- 6.9MediumCVSS base score
- 0.40%Exploitation in 30 daysEPSS · top 65% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. 2 references of the record are tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits2
Timeline
ID reserved
By VulDB
- 1 day later
· 1 day later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Medium6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P |
| VulDBCNA (assigner) | 3.1 | High7.3 | 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 |
| VulDBCNA (assigner) | 3.0 | High7.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C |
| VulDBCNA (assigner) | 2.0 | High7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P/E:POC/RL:OF/RC:C |
| NVDNVD · Deferred | 4.0 | Medium5.5 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.40% · top 65% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.9.
Affected products
- affected 4.5.0
References
References8
- VDB-394543 | warmcat libwebsockets LECP CBOR Recording lecp.c report_raw_cbor out-of-bounds write (opens in a new tab)vdb-entrytechnical-description
- VDB-394543 | CTI Indicators (IOB, IOC, IOA) (opens in a new tab)signaturepermissions-required
- CVE-2026-78161 | CVE Analysis and Report (opens in a new tab)third-party-advisory
- Submit #883225 | warmcat libwebsockets 4.5.99-v4.5.0-508-gb4b5aed39 Out-of-bounds Write (opens in a new tab)third-party-advisory
- https://github.com/biniamf/pocs/tree/main/libwebsockets-lecp-lecp_parse-cbor_pos_oob_write (opens in a new tab)exploit
- https://github.com/biniamf/pocs/blob/main/libwebsockets-lecp-lecp_parse-cbor_pos_oob_write/poc_lecp_cbor_pos_oob.c (opens in a new tab)exploit
- https://github.com/warmcat/libwebsockets/commit/1d44554a1bb262db63ff4e240152a9deecd99054 (opens in a new tab)patch
- https://github.com/warmcat/libwebsockets/ (opens in a new tab)product
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-64685 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-78161)Record last updated .