CVE-2023-40890: zbar · Out-of-bounds Write
Affects zbarSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 1.9% chance of exploitation in 30 days – higher than 80% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 29 Aug 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Debiandebian/zbarpkg:deb/debian/zbarOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Given the absence of an official patch, European organizations should implement several targeted mitigations: 1) Restrict QR code scanning to trusted sources and environments, avoiding scanning codes from unverified or public origins. 2) Employ input validation and sanitization layers before passing QR code data to ZBar to detect and reject malformed or suspicious codes. 3) Use application-level sandboxing or containerization to isolate the scanning process and limit the impact of potential exploitation. 4) Monitor scanning device logs and network traffic for anomalies indicative of exploitation attempts. 5) Where possible, replace or upgrade to alternative QR code scanning libraries that are not vulnerable. 6) Engage with vendors and developers to expedite patch development and deployment. 7) Conduct security awareness training for staff about the risks of scanning unknown QR codes. These measures collectively reduce exposure while awaiting an official fix.
Description
A stack-based buffer overflow vulnerability exists in the lookup_sequence function of ZBar 0.23.90. Specially crafted QR codes may lead to information disclosure and/or arbitrary code execution. To trigger this vulnerability, an attacker can digitally input the malicious QR code, or prepare it to be physically scanned by the vulnerable scanner.
References
- hackmd.io/%40cspl/H1PxPAUnn (opens in a new tab)
- lists.debian.org/debian-lts-announce/2023/12/msg00001.html (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/25LZZQJGGZRPLKTRNRNOTAFQJIPS7WRP/ (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DC7V5YCLCPB36J2KY6WLZCABFLBRB665/ (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DC7V5YCLCPB36J2KY6WLZCABFLBRB665/ (opens in a new tab)