GHSA-6878-6wc2-pf5h is a medium-severity (CVSS 4.5) CWE-323 vulnerability in cocoon. A fix is available for cocoon — see the affected versions and patch details below.
Sequential calls of encryption API (`encrypt`, `wrap`, and `dump`) result in nonce reuse
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-6878-6wc2-pf5h.
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
GHSA-6878-6wc2-pf5h 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 379,145 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
cocoonReal-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
Problem: Trying to create a new encrypted message with the same cocoon object generates the same ciphertext. It mostly affects MiniCocoon and Cocoon objects with custom seeds and RNGs (where StdRng is used under the hood).
Note: The issue does NOT affect objects created with Cocoon::new which utilizes ThreadRng.
Cause: StdRng produces the same nonce because StdRng::clone resets its state.
Measure: Make encryption API mutable (encrypt, wrap, and dump).
Workaround: Create a new cocoon object with a new seed per each encryption.
How to Reproduce
let cocoon = MiniCocoon::from_password(b"password", &[1; 32]);
let mut data1 = "my secret data".to_owned().into_bytes();
let _ = cocoon.encrypt(&mut data1)?;
let mut data2 = "my secret data".to_owned().into_bytes();
let _ = cocoon.encrypt(&mut data2)?;
// data1: [23, 217, 251, 151, 179, 62, 85, 15, 253, 92, 192, 112, 200, 52]
// data2: [23, 217, 251, 151, 179, 62, 85, 15, 253, 92, 192, 112, 200, 52]
Workaround
For cocoon <= 0.3.3, create a new cocoon with a different seed per each encrypt/wrap/dump call.
let cocoon = MiniCocoon::from_password(b"password", &[1; 32]);
let mut data1 = "my secret data".to_owned().into_bytes();
let _ = cocoon.encrypt(&mut data1)?;
// Another seed: &[2; 32].
let cocoon = MiniCocoon::from_password(b"password", &[2; 32]);
let mut data2 = "my secret data".to_owned().into_bytes();
let _ = cocoon.encrypt(&mut data2)?;
// data1: [23, 217, 251, 151, 179, 62, 85, 15, 253, 92, 192, 112, 200, 52]
// data2: [53, 223, 209, 96, 130, 99, 209, 108, 83, 189, 123, 81, 19, 1]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | cocoon | all versions | 0.4.0cargo update -p cocoon --precise 0.4.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for cocoon, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update cocoon to 0.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6878-6wc2-pf5h 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 GHSA-6878-6wc2-pf5h can be triaged on real exposure rather than presence alone.
Tailored to GHSA-6878-6wc2-pf5h. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-6878-6wc2-pf5h in your dependencies?
O3 Security finds GHSA-6878-6wc2-pf5h across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.