CVE-2021-28254Public exploitNetwork attack vector

Command execution via deserialization gadget chain

Published Apr 18, 2023 · Updated Mar 5, 2025

A deserialization gadget chain in Laravel 8.5.9 allows remote attackers to execute arbitrary PHP functions through crafted serialized objects. PendingBroadcast::__destruct passes attacker-controlled event data into Dispatcher, whose queue resolver reaches an attacker-selected callable through InvokableComponentVariable. Exploitation requires an application to pass attacker input to PHP unserialize; the published demonstration adds that unsafe route manually, so Laravel alone does not expose it.

CVSS severity9.8
Critical
EPSS probability1.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A deserialization gadget chain in Laravel 8.5.9 allows remote attackers to execute arbitrary PHP functions through crafted serialized objects. PendingBroadcast::__destruct passes attacker-controlled event data into Dispatcher, whose queue resolver reaches an attacker-selected callable through InvokableComponentVariable. Exploitation requires an application to pass attacker input to PHP unserialize; the published demonstration adds that unsafe route manually, so Laravel alone does not expose it.

The record

CVE
CVE-2021-28254
Published
Apr 18, 2023
Updated
Mar 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 18, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8CISA-ADPCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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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