CVE-2023-28428Public exploit

Process hang via stalled flate decompression

Published Mar 20, 2023 · Updated Feb 25, 2025

Denial of service in Michael R Sweet PDFio 1.1.0 and earlier allows attackers to hang a consuming process with a crafted PDF file. The stream_read function repeatedly calls zlib inflate on corrupt flate stream data without detecting that neither input nor output progress occurred. When an application parses the file, the affected process consumes a CPU core indefinitely; reachability depends on that application accepting attacker-supplied PDFs.

CVSS severity3.3
Low
EPSS probability0.22%
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 Michael R Sweet PDFio 1.1.0 and earlier allows attackers to hang a consuming process with a crafted PDF file. The stream_read function repeatedly calls zlib inflate on corrupt flate stream data without detecting that neither input nor output progress occurred. When an application parses the file, the affected process consumes a CPU core indefinitely; reachability depends on that application accepting attacker-supplied PDFs.

The record

CVE
CVE-2023-28428
Published
Mar 20, 2023
Updated
Feb 25, 2025
Vendor
Michael R Sweet
Product
PDFio
Classifications
CWE-770, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 20, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 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=<= 1.1.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Michael R Sweet · PDFioversion=<= 1.1.0

Published CVSS scores

3.3NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
6.2GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:N/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.

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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application 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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