CVE-2024-36400 is a critical-severity (CVSS 9.4) CWE-331 vulnerability in nano-id. 1 public exploit reference exists, so weaponization risk is real. A fix is available for nano-id — see the affected versions and patch details below.
nano-id is unable to generate the correct character set
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-36400.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2024-36400 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
nano-idReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-9hc7-6w9r-wj94. This link is maintained to preserve external references.
Original Description
Description
Affected versions of the nano-id crate incorrectly generated IDs using a reduced character set in the nano_id::base62 and nano_id::base58 functions. Specifically, the base62 function used a character set of 32 symbols instead of the intended 62 symbols, and the base58 function used a character set of 16 symbols instead of the intended 58 symbols. Additionally, the nano_id::gen macro is also affected when a custom character set that is not a power of 2 in size is specified.
It should be noted that nano_id::base64 is not affected by this vulnerability.
Impact
This can result in a significant reduction in entropy, making the generated IDs predictable and vulnerable to brute-force attacks when the IDs are used in security-sensitive contexts such as session tokens or unique identifiers.
Patches
The flaws were corrected in commit a9022772b2f1ce38929b5b81eccc670ac9d3ab23 by updating the the nano_id::gen macro to use all specified characters correctly.
PoC
use std::collections::BTreeSet;
fn main() {
test_base58();
test_base62();
}
fn test_base58() {
let mut produced_symbols = BTreeSet::new();
for _ in 0..100_000 {
id = "RUSTSEC-2024-0343"
for c in id.chars() {
produced_symbols.insert(c);
}
}
println!(
"{} symbols generated from nano_id::base58",
produced_symbols.len()
);
}
fn test_base62() {
let mut produced_symbols = BTreeSet::new();
for _ in 0..100_000 {
id = "RUSTSEC-2024-0343"
for c in id.chars() {
produced_symbols.insert(c);
}
}
println!(
"{} symbols generated from nano_id::base62",
produced_symbols.len()
);
}
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | nano-id | all versions | 0.4.0cargo update -p nano-id --precise 0.4.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nano-id, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nano-id to 0.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-36400 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-36400 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-36400. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-36400 in your dependencies?
O3 Security finds CVE-2024-36400 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.