CVE-2023-26991Public exploit

Crash via expired stack reader dereference

Published Apr 4, 2023 · Updated Feb 12, 2025

Stack-use-after-scope in SWFTools 0.9.2 allows local users to crash swfdump when it processes a crafted SWF file. In swf_ReadSWF2, the reader pointer continues to reference the stack-allocated zreader object after that object's scope ends and dereferences it at lib/rfxswf.c:1607. Exploitation requires a crafted file to be supplied to the parser; the published proof of concept demonstrates an AddressSanitizer abort, not code execution.

CVSS severity7.8
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-use-after-scope in SWFTools 0.9.2 allows local users to crash swfdump when it processes a crafted SWF file. In swf_ReadSWF2, the reader pointer continues to reference the stack-allocated zreader object after that object's scope ends and dereferences it at lib/rfxswf.c:1607. Exploitation requires a crafted file to be supplied to the parser; the published proof of concept demonstrates an AddressSanitizer abort, not code execution.

The record

CVE
CVE-2023-26991
Published
Apr 4, 2023
Updated
Feb 12, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416, T1203
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Apr 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 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 privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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.

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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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

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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