NIP-04 parsing amplifies malformed ciphertext memory use

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

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…

Published by the source

1 Aug 2026, 12:00 UTC

Last modified by the source

2 Aug 2026, 18:00 UTC

Source last checked

23 Oct 2026, 22:04 UTC

1. Revision 1 · created · 24 Oct 2026

   Published from osv record RUSTSEC-2026-0228

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# Patch Next advisory brief: rustsec-2026-0228

Advisory: NIP-04 parsing amplifies malformed ciphertext memory use
IDs: rustsec-2026-0228
Record: https://patchnext.com/advisories/rustsec-2026-0228 (revision 1, source checked 23 Oct 2026, 22:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: nostr 0.44.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io nostr: affected >= 0.0.0-0, < 0.44.7; fixed in 0.44.7

## Suggested inspection (read-only)
- crates.io nostr: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on nostr.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/RUSTSEC-2026-0228 (OSV record RUSTSEC-2026-0228 lists affected ranges: crates.io nostr >=0.0.0-0 <0.44.7 (fixed))

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