CVE-2025-27520Public exploitNetwork attack vector

Unauthenticated code execution via HTTP pickle deserialization

Published Apr 4, 2025 · Updated Apr 4, 2025

Insecure deserialization in BentoML 1.3.4 through 1.4.2 allows remote attackers to execute arbitrary server-side code via HTTP requests. The main server's deserialize_value path passes attacker-controlled request bytes to pickle.loads when buffer-lengths metadata is absent. No authentication or user interaction is required, and successful exploitation runs code with the BentoML service process's privileges.

CVSS severity9.8
Critical
EPSS probability40.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insecure deserialization in BentoML 1.3.4 through 1.4.2 allows remote attackers to execute arbitrary server-side code via HTTP requests. The main server's deserialize_value path passes attacker-controlled request bytes to pickle.loads when buffer-lengths metadata is absent. No authentication or user interaction is required, and successful exploitation runs code with the BentoML service process's privileges.

The record

CVE
CVE-2025-27520
Published
Apr 4, 2025
Updated
Apr 4, 2025
Vendor
BentoML
Product
BentoML
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 1.3.4, < 1.4.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

BentoML · BentoMLversion=>= 1.3.4, < 1.4.3

Published CVSS scores

9.8GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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