CVE-2023-26151 is a medium-severity (CVSS 5.3) Uncontrolled Resource Consumption vulnerability in asyncua. 3 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for asyncua — see the affected versions and patch details below.
asyncua vulnerable to denial of service via infinite loop
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 CVE-2023-26151.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
asyncuaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Versions of the package asyncua before 0.9.96 are vulnerable to Denial of Service (DoS) such that an attacker can send a malformed packet and as a result, the server will enter into an infinite loop and consume excessive memory.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | asyncua | all versions | 0.9.96pip install --upgrade 'asyncua==0.9.96' |
Affected Products
opcua-asynciofreeopcuaResearch 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 asyncua, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update asyncua to 0.9.96 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26151 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2023-26151 in your dependencies?
Find it across PyPI, including transitive dependencies.