CVE catalog
CVE-2026-20243
A vulnerability in the ALZ file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption o
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.57% · Oct 25, 2026
A vulnerability in the ALZ file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in ALZ files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains ALZ content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | clamav | sid | 1.4.6+dfsg-1 | fixed |
| Debian | clamav | forky | 1.4.6+dfsg-1 | fixed |
| Debian | clamav | trixie | 1.4.3+dfsg-1 | vulnerable |
| Debian | clamav | bookworm | 1.4.3+dfsg-1~deb12u2 | vulnerable |
| Debian | clamav | bookworm-security | 1.4.6+dfsg-0+deb12u1 | fixed |
| Cpe | clamav | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | clamav-base | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | clamav-daemon | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | clamav-doc | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | clamav-docs | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | clamav-freshclam | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | clamav-milter | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | clamav-testfiles | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | clamdscan | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | libclamav-dev | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | libclamav12 | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Cpe | clamav | Not reported | Not reported | vulnerable |
| Cpe | secure_endpoint | Not reported | 1.27.2 | fixed |
| Cpe | secure_endpoint | Not reported | 1.29.0 | fixed |
| Cpe | secure_endpoint | Not reported | 8.6.2 | fixed |
| Cpe | clamav | Not reported | 1.4.5 | fixed |
| Cpe | clamav | Not reported | 1.5.3 | fixed |
| Ubuntu | clamav | pro | 0.101.4+dfsg-1ubuntu1 | vulnerable |
| Ubuntu | clamav | pro | 0.102.1+dfsg-1ubuntu1 | vulnerable |
| Ubuntu | clamav | pro | 0.102.1+dfsg-2ubuntu1 | vulnerable |
| Ubuntu | clamav | pro | 0.102.1+dfsg-2ubuntu2 | vulnerable |
| Ubuntu | clamav | pro | 0.102.2+dfsg-1ubuntu1 | vulnerable |
| Ubuntu | clamav | pro | 0.102.2+dfsg-2ubuntu1 | vulnerable |
| Ubuntu | clamav | pro | 0.102.3+dfsg-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | clamav | pro | 0.102.4+dfsg-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | clamav | pro | 0.103.2+dfsg-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | clamav | pro | 0.103.2+dfsg-0ubuntu0.20.04.2 | vulnerable |
| Ubuntu | clamav | pro | 0.103.5+dfsg-1~20.04.1 | vulnerable |
| Ubuntu | clamav | pro | 0.103.6+dfsg-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | clamav | pro | 0.103.8+dfsg-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | clamav | pro | 0.103.9+dfsg-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | clamav | pro | 0.103.11+dfsg-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | clamav | pro | 0.103.12+dfsg-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | clamav | pro | 1.4.3+dfsg-0ubuntu0.20.04.1+esm1 | vulnerable |
| Ubuntu | clamav | 22.04 | 0.103.3+dfsg-1 | vulnerable |
| Ubuntu | clamav | 22.04 | 0.103.4+dfsg-1 | vulnerable |
| Ubuntu | clamav | 22.04 | 0.103.4+dfsg-1build1 | vulnerable |
| Ubuntu | clamav | 22.04 | 0.103.5+dfsg-1 | vulnerable |
| Ubuntu | clamav | 22.04 | 0.103.6+dfsg-0ubuntu0.22.04.1 | vulnerable |
| Ubuntu | clamav | 22.04 | 0.103.8+dfsg-0ubuntu0.22.04.1 | vulnerable |
| Ubuntu | clamav | 22.04 | 0.103.9+dfsg-0ubuntu0.22.04.1 | vulnerable |
| Ubuntu | clamav | 22.04 | 0.103.11+dfsg-0ubuntu0.22.04.1 | vulnerable |
| Ubuntu | clamav | 22.04 | 0.103.12+dfsg-0ubuntu0.22.04.1 | vulnerable |
| Ubuntu | clamav | 22.04 | 1.4.3+dfsg-0ubuntu0.22.04.1 | vulnerable |
| Ubuntu | clamav | 22.04 | 1.4.4+dfsg-0ubuntu0.22.04.1 | vulnerable |
| Ubuntu | clamav | 22.04 | 1.5.3+dfsg-0ubuntu0.22.04.2 | fixed |
| Ubuntu | clamav | 24.04 | 1.0.2+dfsg-1ubuntu1 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.0.3+dfsg-2ubuntu1 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.0.4+dfsg-0ubuntu1 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.0.5+dfsg-1ubuntu1 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.0.5+dfsg-1.1ubuntu2 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.0.5+dfsg-1.1ubuntu3 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.0.7+dfsg-0ubuntu0.24.04.1 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.0.8+dfsg-0ubuntu0.24.04.1 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.4.3+dfsg-0ubuntu0.24.04.1 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.4.4+dfsg-0ubuntu0.24.04.1 | vulnerable |
| Ubuntu | clamav | 24.04 | 1.5.3+dfsg-0ubuntu0.24.04.1 | fixed |
| Ubuntu | clamav | 25.10 | 1.4.2+dfsg-0ubuntu1 | vulnerable |
| Ubuntu | clamav | 25.10 | 1.4.2+dfsg-0ubuntu2 | vulnerable |
| Ubuntu | clamav | 25.10 | 1.4.2+dfsg-1ubuntu1 | vulnerable |
| Ubuntu | clamav | 25.10 | 1.4.3+dfsg-0ubuntu1 | vulnerable |
| Ubuntu | clamav | 25.10 | 1.4.3+dfsg-0ubuntu2 | vulnerable |
| Ubuntu | clamav | 25.10 | 1.4.4+dfsg-0ubuntu0.25.10.1 | vulnerable |
| Ubuntu | clamav | 26.04 | 1.4.3+dfsg-0ubuntu2 | vulnerable |
| Ubuntu | clamav | 26.04 | 1.4.3+dfsg-0ubuntu3 | vulnerable |
| Ubuntu | clamav | 26.04 | 1.4.3+dfsg-2ubuntu1 | vulnerable |
| Ubuntu | clamav | 26.04 | 1.4.3+dfsg-2ubuntu2 | vulnerable |
| Ubuntu | clamav | 26.04 | 1.4.3+dfsg-2ubuntu3 | vulnerable |
| Ubuntu | clamav | 26.04 | 1.4.4+dfsg-0ubuntu0.26.04.1 | vulnerable |
| Ubuntu | clamav | 26.04 | 1.5.3+dfsg-0ubuntu0.26.04.1 | fixed |
| Cpe | secure_endpoint | Not reported | 8.6.2 | fixed |
| Cpe | clamav | Not reported | 1.5.3 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | clamav | source | sid | 1.4.5+dfsg-1 | not yet assigned | Not reported | [1141303] |
| Debian | clamav | source | forky | 1.4.5+dfsg-1 | not yet assigned | Not reported | [1141303] |
| Debian | clamav | source | trixie | (unfixed) | not yet assigned | Not reported | [1141303] |
| Debian | clamav | source | bookworm | 1.4.6+dfsg-0+deb12u1 | not yet assigned | Not reported | [1141303] |
| Cpe | clamav | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | clamav-base | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | clamav-daemon | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | clamav-doc | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | clamav-docs | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | clamav-freshclam | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | clamav-milter | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | clamav-testfiles | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | clamdscan | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | libclamav-dev | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | libclamav12 | cpe | Not reported | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | Not reported | Not reported |
| Cpe | secure_endpoint | cpe | Not reported | 1.27.2 | Not reported | Not reported | Not reported |
| Cpe | secure_endpoint | cpe | Not reported | 1.29.0 | Not reported | Not reported | Not reported |
| Cpe | secure_endpoint | cpe | Not reported | 8.6.2 | Not reported | Not reported | Not reported |
| Cpe | clamav | cpe | Not reported | 1.4.5 | Not reported | Not reported | Not reported |
| Cpe | clamav | cpe | Not reported | 1.5.3 | Not reported | Not reported | Not reported |
| Ubuntu | clamav | deb | 22.04 | 1.5.3+dfsg-0ubuntu0.22.04.2 | Not reported | UBUNTU-CVE-2026-20243 | Not reported |
| Ubuntu | clamav | deb | 24.04 | 1.5.3+dfsg-0ubuntu0.24.04.1 | Not reported | UBUNTU-CVE-2026-20243 | Not reported |
| Ubuntu | clamav | deb | 26.04 | 1.5.3+dfsg-0ubuntu0.26.04.1 | Not reported | UBUNTU-CVE-2026-20243 | Not reported |
| Cpe | secure_endpoint | cpe | Not reported | 8.6.2 | Not reported | NVD-CVE-2026-20243 | Not reported |
| Cpe | clamav | cpe | Not reported | 1.5.3 | Not reported | NVD-CVE-2026-20243 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [clamav]Affected
Details (2)
1.4.3+dfsg-1~deb12u2· amd64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· arm64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [clamav-base]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· all · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· all · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [clamav-daemon]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· amd64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· arm64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [clamav-doc]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· all · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· all · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [clamav-docs]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· all · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· all · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [clamav-freshclam]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· amd64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· arm64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [clamav-milter]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· amd64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· arm64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [clamav-testfiles]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· all · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· all · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [clamdscan]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· amd64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· arm64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [libclamav12]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· amd64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· arm64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
- [libclamav-dev]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1~deb12u2· amd64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
1.4.3+dfsg-1~deb12u2· arm64 · bookwormAffected · Fixed:
1.4.6+dfsg-0+deb12u1nvd · clamav · debian · bookworm; nvd · clamav · debian · 12
[Debian 13 (Trixie)]
- [clamav]Affected
Details (2)
1.4.3+dfsg-1· amd64 · trixieAffected
nvd · clamav · debian · 13
1.4.3+dfsg-1· arm64 · trixieAffected
nvd · clamav · debian · 13
- [clamav-base]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1· all · trixieAffected
nvd · clamav · debian · 13
1.4.3+dfsg-1· all · trixieAffected
nvd · clamav · debian · 13
- [clamav-daemon]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1· amd64 · trixieAffected
nvd · clamav · debian · 13
1.4.3+dfsg-1· arm64 · trixieAffected
nvd · clamav · debian · 13
- [clamav-doc]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1· all · trixieAffected
nvd · clamav · debian · 13
1.4.3+dfsg-1· all · trixieAffected
nvd · clamav · debian · 13
- [clamav-docs]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1· all · trixieAffected
nvd · clamav · debian · 13
1.4.3+dfsg-1· all · trixieAffected
nvd · clamav · debian · 13
- [clamav-freshclam]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1· amd64 · trixieAffected
nvd · clamav · debian · 13
1.4.3+dfsg-1· arm64 · trixieAffected
nvd · clamav · debian · 13
- [clamav-milter]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1· amd64 · trixieAffected
nvd · clamav · debian · 13
1.4.3+dfsg-1· arm64 · trixieAffected
nvd · clamav · debian · 13
- [clamav-testfiles]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1· all · trixieAffected
nvd · clamav · debian · 13
1.4.3+dfsg-1· all · trixieAffected
nvd · clamav · debian · 13
- [clamdscan]Affected
Source package: [clamav]
Details (2)
1.4.3+dfsg-1· amd64 · trixieAffected
nvd · clamav · debian · 13
1.4.3+dfsg-1· arm64 · trixieAffected
nvd · clamav · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2026_2834-2.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-20243]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-20243]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-20243]
- [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-88cFYyxR]
- [https://security-tracker.debian.org/tracker/CVE-2026-20243]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-20243.json]
- [https://ubuntu.com/security/notices/USN-8517-1]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2173.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]