Improper Input Validation Affecting litellm package, versions <1.89.0-r2


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.18% (8th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-LITELLM-17376268
  • published19 Jun 2026
  • disclosed22 Jun 2026

Introduced: 19 Jun 2026

NewCVE-2026-53537  (opens in a new tab)
CWE-20  (opens in a new tab)
CWE-436  (opens in a new tab)

How to fix?

Upgrade Chainguard litellm to version 1.89.0-r2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream litellm package and not the litellm package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, parse_options_header parsed Content-Disposition (and Content-Type) headers with email.message.Message, which transparently applies RFC 2231/5987 decoding. The extended parameter syntax (filename*=charset'lang'value, name*=..., and the filename0/filename1 continuation form) is decoded and surfaced under the bare filename/name key, and overrides the plain parameter when both are present. RFC 7578 §4.2 explicitly forbids the filename* form in multipart/form-data. Components that follow RFC 7578, or that do not implement RFC 2231/5987 decoding for multipart/form-data (WAFs, proxies, gateways), may interpret such a header differently. An attacker can exploit that difference to smuggle a different field name or filename past an upstream inspector to the backend. This vulnerability is fixed in 0.0.30.

CVSS Base Scores

version 3.1