rustsec-2026-0227
Vulnerability from osv_rustsec
The NIP-44 decryption entry point Base64-decoded the complete attacker-controlled payload before determining its version or enforcing any size limit. For v2 payloads, the decoded buffer was then authenticated with HMAC even when it was much larger than the maximum payload supported by the crate's current v2 codec.
A malicious relay or event author could deliver an oversized value to an application that decrypts NIP-44 content. The value caused memory allocation and Base64 and HMAC work proportional to its size before authentication failed; knowledge of the conversation key was not required to consume those initial resources. Repeated payloads could exhaust memory or CPU and make the receiving application unavailable. The issue does not disclose plaintext or key material and does not bypass message authentication.
Decryption now reads only the encoded version prefix first, derives the bound from the largest payload the current v2 encoder can emit, and rejects oversized encoded and decoded payloads before full allocation or HMAC processing. The limit remains in the v2 implementation so a future codec with a different length format can define its own bound.
{
"affected": [
{
"database_specific": {
"categories": [
"denial-of-service"
],
"cvss": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"informational": null
},
"ecosystem_specific": {
"affected_functions": null,
"affects": {
"arch": [],
"functions": [],
"os": []
}
},
"package": {
"ecosystem": "crates.io",
"name": "nostr",
"purl": "pkg:cargo/nostr"
},
"ranges": [
{
"events": [
{
"introduced": "0.0.0-0"
},
{
"fixed": "0.44.7"
}
],
"type": "SEMVER"
}
],
"versions": []
}
],
"aliases": [],
"database_specific": {
"license": "CC0-1.0"
},
"details": "The NIP-44 decryption entry point Base64-decoded the complete attacker-controlled\npayload before determining its version or enforcing any size limit. For v2 payloads,\nthe decoded buffer was then authenticated with HMAC even when it was much larger than\nthe maximum payload supported by the crate\u0027s current v2 codec.\n\nA malicious relay or event author could deliver an oversized value to an application\nthat decrypts NIP-44 content. The value caused memory allocation and Base64 and HMAC\nwork proportional to its size before authentication failed; knowledge of the\nconversation key was not required to consume those initial resources. Repeated\npayloads could exhaust memory or CPU and make the receiving application unavailable.\nThe issue does not disclose plaintext or key material and does not bypass message\nauthentication.\n\nDecryption now reads only the encoded version prefix first, derives the bound from\nthe largest payload the current v2 encoder can emit, and rejects oversized encoded\nand decoded payloads before full allocation or HMAC processing. The limit remains in\nthe v2 implementation so a future codec with a different length format can define its\nown bound.",
"id": "RUSTSEC-2026-0227",
"modified": "2026-08-02T17:56:20Z",
"published": "2026-08-01T12:00:00Z",
"references": [
{
"type": "PACKAGE",
"url": "https://crates.io/crates/nostr"
},
{
"type": "ADVISORY",
"url": "https://rustsec.org/advisories/RUSTSEC-2026-0227.html"
},
{
"type": "WEB",
"url": "https://github.com/nostrdevkit/nostr/commit/89dc1a77eaa774174588c5a38b6324c502948830"
}
],
"related": [],
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "NIP-44 v2 decryption permits resource exhaustion"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.