How severe is CVE-2026-40217?

CVE-2026-40217 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-40217 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40217?

CVE-2026-40217 affects Litellm. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-40217?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-40217 have an EU (EUVD) identifier?

Yes. CVE-2026-40217 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21376.

When was CVE-2026-40217 published?

CVE-2026-40217 was published on 2026-04-10 and last updated on 2026-06-30.

CVE-2026-40217

CVE-2026-40217 is a high-severity vulnerability in Litellm with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-420.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 6% (93rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21376
Weakness: CWE-420
Affected product: Litellm
Published: 2026-04-10
Last modified: 2026-06-30

Description

LiteLLM through 2026-04-08 allows remote attackers to execute arbitrary code via bytecode rewriting at the /guardrails/test_custom_code URI.

Frequently asked questions

What is CVE-2026-40217?: LiteLLM through 2026-04-08 allows remote attackers to execute arbitrary code via bytecode rewriting at the /guardrails/test_custom_code URI.
How severe is CVE-2026-40217?: CVE-2026-40217 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-40217 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40217?: CVE-2026-40217 affects Litellm. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-40217?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-40217 have an EU (EUVD) identifier?: Yes. CVE-2026-40217 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21376.
When was CVE-2026-40217 published?: CVE-2026-40217 was published on 2026-04-10 and last updated on 2026-06-30.

References

Affected products (1)

cpe:2.3:a:litellm:litellm:*:*:*:*:*:*:*:*

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