CVE-2024-23838 is a high-severity (CVSS 8.6) Server-Side Request Forgery (SSRF) vulnerability in TrueLayer.Client. A fix is available for TrueLayer.Client — see the affected versions and patch details below.
TrueLayer.Client SSRF when fetching payment or payment provider
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.
- 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-2024-23838.
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
TrueLayer.ClientReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
TrueLayer.NET is the .Net client for TrueLayer. The vulnerability could potentially allow a malicious actor to gain control over the destination URL of the HttpClient used in the API classes. For applications using the SDK, requests to unexpected resources on local networks or to the internet could be made which could lead to information disclosure. The issue can be mitigated by having strict egress rules limiting the destinations to which requests can be made, and applying strict validation to any user input passed to the truelayer-dotnet library. Versions of TrueLayer.Client v1.6.0 and later are not affected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | TrueLayer.Client | all versions | 1.6.0dotnet add package TrueLayer.Client --version 1.6.0 |
Affected Products
truelayer.nettruelayerDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for TrueLayer.Client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update TrueLayer.Client to 1.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-23838 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.
Frequently Asked Questions
Is CVE-2024-23838 in your dependencies?
Find it across NuGet, including transitive dependencies.