CVE-2022-31628Public exploit

Worker hang via recursive gzip decompression

Published Sep 28, 2022 · Updated May 20, 2025

Denial of service in PHP 7.4 before 7.4.31, 8.0 before 8.0.24, and 8.1 before 8.1.11 allows local users to hang a worker. In ext/phar/phar.c, a loop keeps decompressing output that remains gzip data without a recursion limit to stop a self-reproducing archive. Triggering requires a crafted archive to reach PHAR processing through the phar wrapper or PharData, after which the affected PHP worker consumes CPU indefinitely.

CVSS severity2.3
Low
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in PHP 7.4 before 7.4.31, 8.0 before 8.0.24, and 8.1 before 8.1.11 allows local users to hang a worker. In ext/phar/phar.c, a loop keeps decompressing output that remains gzip data without a recursion limit to stop a self-reproducing archive. Triggering requires a crafted archive to reach PHAR processing through the phar wrapper or PharData, after which the affected PHP worker consumes CPU indefinitely.

The record

CVE
CVE-2022-31628
Published
Sep 28, 2022
Updated
May 20, 2025
Vendor
The PHP Group
Product
PHP
Classifications
CWE-674, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 28, 2022CVE publishedPublication date reported by the CVE source.
  2. May 20, 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=7.4.X <7.4.31
  2. Affected versionversion=8.0.X <8.0.24
  3. Affected versionversion=8.1.X <8.1.11

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The PHP Group · PHPversion=7.4.X <7.4.31; version=8.0.X <8.0.24; version=8.1.X <8.1.11

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
2.3The PHP GroupCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L
5.5OracleCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-674Uncontrolled Recursion
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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