GHSA-wrqv-pf6j-mqjp is a high-severity (CVSS 7.2) CWE-488 vulnerability in deno. 1 public exploit reference exists, so weaponization risk is real. A fix is available for deno — see the affected versions and patch details below.
Deno's Node.js Compatibility Runtime has Cross-Session Data Contamination
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-wrqv-pf6j-mqjp.
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-wrqv-pf6j-mqjp 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 377,333 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
denoReal-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
Summary
A vulnerability in Deno's Node.js compatibility runtime allows for cross-session data contamination during simultaneous asynchronous reads from Node.js streams sourced from sockets or files. The issue arises from the re-use of a global buffer (BUF) in stream_wrap.ts used as a performance optimization to limit allocations during these asynchronous read operations. This can lead to data intended for one session being received by another session, potentially resulting in data corruption and unexpected behavior.
Details
A bug in Deno's Node.js compatibility runtime results in data cross-reception during simultaneous asynchronous reads from Node.js network streams. When multiple independent network socket connections are involved, this vulnerability can be triggered. For instance, two separate server sockets that receive data from their respective client sockets and then echo the received data back to the client using Node.js streams may experience an issue where data from one socket may appear on another socket. Due to the improper isolation of the global buffer (BUF), data sent by one socket can end up being incorrectly received by another socket. Consequently, data intended for one session may be exposed to another session, potentially leading to data corruption and unexpected behavior.
This buffer was introduced as a performance optimization to avoid excessive allocations during network read operations.
In cases where the net.Stream is connected to a remote server such as a database or key/value store such as Redis, this may result in a packet received on one connection being presented to another, causing data cross-contamination between multiple users and potentially leaking sensitive information.
It is important to note that this vulnerability does not affect Deno network streams created with the Deno.listen and Deno.connect APIs.
The impact of this issue may extend beyond node.js network streams, however, and may also affect asynchronous reads from non-network node.js Stream such as those created from files.
PoC
https://github.com/denoland/deno/issues/20188
Impact
This affects all users of Deno that use the node.js compatibility layer for network communication or other streams, including packages that may require node.js libraries indirectly.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | deno | ≥ 1.35.1&&< 1.36.3 | 1.36.3cargo update -p deno --precise 1.36.3 |
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 deno, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update deno to 1.36.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wrqv-pf6j-mqjp 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-wrqv-pf6j-mqjp can be triaged on real exposure rather than presence alone.
Tailored to GHSA-wrqv-pf6j-mqjp. 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-wrqv-pf6j-mqjp in your dependencies?
O3 Security finds GHSA-wrqv-pf6j-mqjp across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.