CVE-2023-40890Public exploitNetwork attack vector

Code execution and disclosure via unchecked array bound

Published Aug 29, 2023 · Updated Nov 4, 2025

Stack-based buffer overflow in ZBar 0.23.90 allows attackers to disclose memory or execute code through a crafted QR code. The lookup_sequence function derives n from segment data and writes through its fixed 22-element seq array without first ensuring n is below 21. Triggering requires a crafted code to be supplied digitally or placed before a physical scanner, after which decoding can expose memory or run code in the scanning process.

CVSS severity9.8
Critical
EPSS probability1.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in ZBar 0.23.90 allows attackers to disclose memory or execute code through a crafted QR code. The lookup_sequence function derives n from segment data and writes through its fixed 22-element seq array without first ensuring n is below 21. Triggering requires a crafted code to be supplied digitally or placed before a physical scanner, after which decoding can expose memory or run code in the scanning process.

The record

CVE
CVE-2023-40890
Published
Aug 29, 2023
Updated
Nov 4, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 29, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.1Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
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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