RUSTSEC-2026-0228
NIP-04 parsing amplifies malformed ciphertext memory use
The NIP-04 decryption parser split attacker-controlled content on every ?iv=
separator and collected all resulting segments before checking that the message had
the expected two parts. It also Base64-decoded the complete IV text before checking
that it represented the required 16-byte AES-CBC IV.
A malicious sender could include a large number of separators or an oversized IV in an encrypted direct message. Applications that attempted to decrypt the message performed avoidable allocations proportional to the malformed input, with additional allocation amplification from the segment vector and Base64 output. This can consume memory and CPU in clients processing messages received through a relay. It does not weaken NIP-04 encryption or reveal plaintext or key material.
The parser now uses a single bounded split, rejects additional separators, and validates the 24-byte encoded IV length before Base64 decoding. Malformed inputs are returned as errors without allocating for every separator or decoding an arbitrarily large IV.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
What each source reports
OSV Score used
NIP-04 parsing amplifies malformed ciphertext memory use
The NIP-04 decryption parser split attacker-controlled content on every ?iv=
separator and collected all resulting segments before checking that the message had
the expected two parts. It also Base64-decoded the complete IV text before checking
that it represented the required 16-byte AES-CBC IV.
A malicious sender could include a large number of separators or an oversized IV in an encrypted direct message. Applications that attempted to decrypt the message performed avoidable allocations proportional to the malformed input, with additional allocation amplification from the segment vector and Base64 output. This can consume memory and CPU in clients processing messages received through a relay. It does not weaken NIP-04 encryption or reveal plaintext or key material.
The parser now uses a single bounded split, rejects additional separators, and validates the 24-byte encoded IV length before Base64 decoding. Malformed inputs are returned as errors without allocating for every separator or decoding an arbitrarily large IV.
- Record
RUSTSEC-2026-0228- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nostrcrates.io |
0.0.0-0 up to 0.44.7 | 0.44.7 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
RUSTSEC-2026-0228 is a medium vulnerability (CVSS 4.3) in nostr, published August 1, 2026. No source lists public exploit code. Fixed in nostr 0.44.7.