CVE-2023-24621Public exploit

Code execution via YAML class-tag override

Published Aug 25, 2023 · Updated Oct 2, 2024

Unsafe deserialization in Esoteric YamlBeans 1.15 and earlier allows attackers to instantiate Java classes through crafted YAML. YamlReader honors a YAML class tag over the class supplied to read(), invokes its public no-argument constructor, and populates fields through setters. Exploitation requires an application to process attacker-authored YAML and a usable JavaBeans gadget, enabling code execution in that application's context.

CVSS severity7.8
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe deserialization in Esoteric YamlBeans 1.15 and earlier allows attackers to instantiate Java classes through crafted YAML. YamlReader honors a YAML class tag over the class supplied to read(), invokes its public no-argument constructor, and populates fields through setters. Exploitation requires an application to process attacker-authored YAML and a usable JavaBeans gadget, enabling code execution in that application's context.

The record

CVE
CVE-2023-24621
Published
Aug 25, 2023
Updated
Oct 2, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-502, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1203Exploitation for Client Execution

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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