RUSTSEC-2026-0224: Verification cache poisoning allows forged Nostr events to bypass signature validation

What to do

1. See which version you have: cargo tree -i nostr-relay-pool (it also shows which of your dependencies pulls it in).
2. Update within your version requirement: cargo update -p nostr-relay-pool. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for example nostr-relay-pool = "0.44.2") or update the dependency that pulls it in.
3. Check again with cargo audit, or paste your Cargo.lock into our Cargo.toml checker.

Details from the advisory

The nostr-relay-pool crate cached the result of event signature verification before the check was actually performed. Because the entry was inserted unconditionally, a first delivery whose signature failed was still recorded in the cache. A subsequent delivery of the same event (identical ID, but with a forged signature) would then hit the cache, causing signature verification to be skipped entirely. The forged event was passed on to NostrDatabase::save_event() as if it had been validated.

Applications that connect to untrusted or compromised Nostr relays and persist received events are vulnerable. An attacker can inject arbitrary events without a valid signature into the application's trusted database, enabling impersonation of any public key or corruption of application state derived from stored events.

The issue does not compromise confidentiality or availability. It solely undermines the integrity of stored event data.

The fix, released in version 0.44.2, moves the cache insertion to occur only after a successful signature verification, so that failed attempts never create a cache entry.

Credit

Discovered and reported by Ali Al-Sorehi

References

• Package: crates.io/crates/nostr-relay-pool
• Advisory: rustsec.org/advisories/RUSTSEC-2026-0224.html
• Web: github.com/nostrdevkit/nostr/commit/02a88bd5688de058bfba8aa9fb4612441a384eff

From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.

Other advisories for nostr-relay-pool

• Vulnerability HighRUSTSEC-2026-0231 · 2026-08-01Relay authentication challenges can exhaust memory
• Vulnerability HighRUSTSEC-2026-0232 · 2026-08-01Processing of unverified relay events
• UnmaintainedRUSTSEC-2026-0243 · 2026-08-03`nostr-relay-pool` is unmaintained

Full security history of nostr-relay-pool