GHSA-vr64-r9qj-h27f — clojure
HIGHGHSA-vr64-r9qj-h27f is a high-severity (CVSS 7.5) Deserialization of Untrusted Data vulnerability in org.clojure:clojure. A fix is available for org.clojure:clojure — see the affected versions and patch details below.
Reading specially crafted serializable objects from an untrusted source may cause an infinite loop and denial of service
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-vr64-r9qj-h27f.
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-vr64-r9qj-h27f 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 377,238 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
org.clojure:clojure☕org.clojure:clojureReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Any program on the JVM may read serialized objects via java.io.ObjectInputStream.readObject(). Reading serialized objects from an untrusted source is inherently unsafe (this affects any program running on any version of the JVM) and is a prerequisite for this vulnerability.
Clojure classes that represent infinite seqs (Cycle, infinite Repeat, and Iterate) do not define hashCode() and use the parent ASeq.hashCode(), which walks the seq to compute the hash, yielding an infinite loop. Classes like java.util.HashMap call hashCode() on keys during deserialization of a serialized map.
The exploit requires:
- Crafting a serialized HashMap object with an infinite seq object as a key.
- Sending that to a program that reads serialized objects via ObjectInputStream.readObject().
This will cause the program to enter an infinite loop on the reading thread and thus a denial of service (DoS).
The affected Clojure classes (Cycle, Repeat, Iterate) exist in Clojure 1.7.0-1.11.1, 1.12.0-alpha1-1.12.0-alpha8.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.clojure:clojure | ≥ 1.7.0&&< 1.11.2 | 1.11.2org.clojure:clojure:1.11.2 |
| ☕Maven | org.clojure:clojure | ≥ 1.12.0-alpha1&&< 1.12.0-alpha9 | 1.12.0-alpha9org.clojure:clojure:1.12.0-alpha9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.clojure:clojure, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.clojure:clojure to 1.11.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vr64-r9qj-h27f 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-vr64-r9qj-h27f can be triaged on real exposure rather than presence alone.
Tailored to GHSA-vr64-r9qj-h27f. 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-vr64-r9qj-h27f in your dependencies?
O3 Security finds GHSA-vr64-r9qj-h27f across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.