CVE-2026-87733 Other in mirage-crypto-ec
Attackers can forge ECDSA signatures by using the point at infinity as a public key in mirage-crypto-ec, bypassing authentication checks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-87733?
CVE-2026-87733 is a medium-severity vulnerability in OCaml mirage-crypto-ec, published on 9 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An issue was discovered in the mirage-crypto-ec function before 2.2.0 for OCaml. The ECDSA functions {P256,P384,P521}.Dsa.pub_of_octets accept 0x00, the encoding of the point at infinity, as a public key. With that public key, signatures can be forged without a private key.
Weakness: CWE-295
Which versions are affected by CVE-2026-87733?
How do I fix CVE-2026-87733?
Upgrade to a fixed version.
Is CVE-2026-87733 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-87733 exists.
Sources
Also known as DEBIAN-CVE-2026-87733, GHSA-5v5p-5xxr-9xf8, OSEC-2026-13, UBUNTU-CVE-2026-87733.