CVE-2026-40217 LiteLLM has a sandbox escape in custom-code guardrail
Remote attackers can execute arbitrary code via bytecode rewriting in the LiteLLM library, requiring immediate upgrades.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-40217?
CVE-2026-40217 is a high-severity code injection vulnerability in BerriAI LiteLLM, published on 10 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
LiteLLM through 2026-04-08 allows remote attackers to execute arbitrary code via bytecode rewriting at the /guardrails/test_custom_code URI.
Which versions are affected by CVE-2026-40217?
3 open source packages ship an affected version, including litellm. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
litellm PyPI | From 1.81.8 | 1.83.10 |
litellm PyPI | From 1.81.8 | 1.83.10 |
litellm PyPI | From 1.81.8 | 1.83.10 |
Products include Litellm Litellm.
How do I fix CVE-2026-40217?
Upgrade litellm to 1.83.10 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-40217 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40217 exists.
Public exploit code: 1 Nuclei template and 1 proofs of concept on GitHub.
Other vulnerabilities in BerriAI LiteLLM
Sources
Also known as CLEANSTART-2026-IM10707, CLEANSTART-2026-UL91233, ECHO-c6d4-cf5f-a050, GHSA-wxxx-gvqv-xp7p, MINI-377r-r3c8-mhq7, MINI-3vcp-7r7v-gxq6 and 13 more.