CVE-2026-2968Cesanta Mongoose Poly1305 Authentication Tag tls_chacha20.c mg_chacha20_poly1305_decrypt signature verification
- 6.3MediumCVSS base score
- 0.25%Exploitation in 30 daysEPSS · top 83% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
A vulnerability was detected in Cesanta Mongoose up to 7.20. This impacts the function mg_chacha20_poly1305_decrypt of the file /src/tls_chacha20.c of the component Poly1305 Authentication Tag Handler. The manipulation results in improper verification of cryptographic signature. The attack may be launched remotely. This attack is characterized by high complexity. The exploitability is said to be difficult. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
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 | Medium6.3 | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P |
| VulDBCNA (assigner) | 3.1 | Low3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R |
| VulDBCNA (assigner) | 3.0 | Low3.7 | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R |
| VulDBCNA (assigner) | 2.0 | Low2.6 | AV:N/AC:H/Au:N/C:N/I:P/A:N/E:POC/RL:ND/RC:UR |
| NVDNVD · Analyzed | 4.0 | Low2.9 | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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)
- 0.25% · top 83% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.3.
Affected products
References
References5
- VDB-347335 | Cesanta Mongoose Poly1305 Authentication Tag tls_chacha20.c mg_chacha20_poly1305_decrypt signature verification (opens in a new tab)vdb-entrytechnical-description
- VDB-347335 | CTI Indicators (IOB, IOC, IOA) (opens in a new tab)signaturepermissions-required
- Submit #757091 | Cesanta Mongoose Embedded Web Server 7.20 Improper Verification of Cryptographic Signature (opens in a new tab)third-party-advisory
- https://github.com/dwBruijn/CVEs/blob/main/Mongoose/ChaCha20Poly1305.md (opens in a new tab)related
- https://github.com/dwBruijn/CVEs/blob/main/Mongoose/ChaCha20Poly1305.md#poc (opens in a new tab)exploit
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-2026-7584 (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-2026-2968)Record last updated .