CVE-2023-49554Public exploit

Assembler crash via freed macro object dereference

Published Jan 2, 2024 · Updated Jun 18, 2025

Use-after-free in YASM 1.3.0.86.g9def allows context-dependent attackers to crash the assembler with a crafted source file. In do_directive, pp_getline frees a macro object before do_directive reads four bytes from that freed heap allocation. Processing the file is required, and the demonstrated result is an AddressSanitizer abort that interrupts the local assembly process.

CVSS severity5.5
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in YASM 1.3.0.86.g9def allows context-dependent attackers to crash the assembler with a crafted source file. In do_directive, pp_getline frees a macro object before do_directive reads four bytes from that freed heap allocation. Processing the file is required, and the demonstrated result is an AddressSanitizer abort that interrupts the local assembly process.

The record

CVE
CVE-2023-49554
Published
Jan 2, 2024
Updated
Jun 18, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416, T1204.002, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 2, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 18, 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 vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1204.002Malicious File
T1499.004Application or System Exploitation

Public exploit references

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Technologies

Your stack

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Your stack

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