CVE-2026-25750 LangSmith Studio has URL Parameter Injection Vulnerability that Enables Token Theft via Malicious baseUrl
Attackers can steal authentication tokens via malicious links, enabling account takeover and unauthorized access to LangSmith resources.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-25750?
CVE-2026-25750 is a high-severity vulnerability in langchain-ai helm, published on 4 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Langchain Helm Charts are Helm charts for deploying Langchain applications on Kubernetes. Prior to langchain-ai/helm version 0.12.71, a URL parameter injection vulnerability existed in LangSmith Studio that could allow unauthorized access to user accounts through stolen authentication tokens. The vulnerability affected both LangSmith Cloud and self-hosted deployments. Authenticated LangSmith users who clicked on a specially crafted malicious link would have their bearer token, user ID, and workspace ID transmitted to an attacker-controlled server. With this stolen token, an attacker could impersonate the victim and access any LangSmith resources or perform any actions the user was authorized to perform within their workspace. The attack required social engineering (phishing, malicious links in emails or chat applications) to convince users to click the crafted URL. The stolen tokens expired after 5 minutes, though repeated attacks against the same user were possible if they could be convinced to click malicious links multiple times. The fix in version 0.12.71 implements validation requiring user-defined allowed origins for the baseUrl parameter, preventing tokens from being sent to unauthorized servers. No known workarounds are available. Self-hosted customers must upgrade to the patched version.
Weakness: CWE-74
Which versions are affected by CVE-2026-25750?
It affects 1 product.
Products include Langchain Langsmith.
How do I fix CVE-2026-25750?
No fix has been published for CVE-2026-25750 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-25750 being exploited?
There is no known exploitation of CVE-2026-25750 in the wild and no public exploit code.