CVE-2026-2968 Cesanta Mongoose Poly1305 Authentication Tag tls_chacha20.c mg_chacha20_poly1305_decrypt signature verification
Remote attackers can bypass Poly1305 authentication tag verification in Cesanta Mongoose due to improper cryptographic signature checks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-2968?
CVE-2026-2968 is a medium-severity vulnerability in Cesanta Mongoose, published on 23 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-2968?
It affects 1 product.
Products include Cesanta Mongoose.
How do I fix CVE-2026-2968?
No fix published yet.
Is CVE-2026-2968 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-2968 exists.
Other vulnerabilities in Cesanta Mongoose
Sources
Also known as DEBIAN-CVE-2026-2968, GHSA-jprc-mg35-68jq, JLSEC-2026-368, UBUNTU-CVE-2026-2968.