CVE-2020-23546

Application crash via fault-derived function argument

Published Oct 28, 2021 · Updated Jul 9, 2026

Denial of service in the FORMATS plugin for IrfanView 4.54 allows attackers to crash the application by opening a crafted XBM file. The 32-bit FORMATS.dll XBM reader reaches ReadMosaic+0x981 and uses data from a faulting address as an argument to a subsequent function call. Exploitation requires a local user to open the file; public evidence confirms a user-mode access violation but does not establish code execution.

CVSS severity7.8
High
EPSS probability0.96%
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 the FORMATS plugin for IrfanView 4.54 allows attackers to crash the application by opening a crafted XBM file. The 32-bit FORMATS.dll XBM reader reaches ReadMosaic+0x981 and uses data from a faulting address as an argument to a subsequent function call. Exploitation requires a local user to open the file; public evidence confirms a user-mode access violation but does not establish code execution.

The record

CVE
CVE-2020-23546
Published
Oct 28, 2021
Updated
Jul 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1204.002
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 28, 2021CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 2026Record 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 privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1204.002User Execution: Malicious File

Public exploit references

No public exploit references are available in this record.

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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