# CVE-2026-20031: ClamAV CSS Image Parsing Error Handling Denial of Service Vulnerability > An unauthenticated remote attacker can cause a denial of service by submitting a crafted HTML file to ClamAV, terminating the scanning process. - **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Mar 2026 - **Updated:** 5 Mar 2026 - **Also known as:** DEBIAN-CVE-2026-20031, GHSA-hvpm-hv6g-6m5c, MINI-4732-p28x-6h54, MINI-8j36-pr6j-mwcv, SUSE-SU-2026:0906-2, SUSE-SU-2026:1324-1, SUSE-SU-2026:1325-1, SUSE-SU-2026:21358-1, UBUNTU-CVE-2026-20031, USN-8207-1, openSUSE-SU-2026:10325-1, openSUSE-SU-2026:20479-1 ## What is CVE-2026-20031? CVE-2026-20031 is a medium-severity denial of service vulnerability in Cisco Secure Endpoint, published on 4 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A vulnerability in the HTML Cascading Style Sheets (CSS) module of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error handling when splitting UTF-8 strings. An attacker could exploit this vulnerability by submitting a crafted HTML file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the scanning process. Weakness: CWE-248 (Uncaught Exception) ## Which versions are affected by CVE-2026-20031? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `clamav` | SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | All versions | 1.5.2-150400.13.5.1 | | `clamav` | SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS | All versions | 1.5.2-150400.13.5.1 | | `clamav` | SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | All versions | 1.5.2-150400.13.5.1 | | `clamav` | SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS | All versions | 1.5.2-150400.13.5.1 | | `clamav` | SUSE:Linux Enterprise Module for Basesystem 15 SP7 | All versions | 1.5.2-150600.18.25.1 | | `clamav` | SUSE:Linux Enterprise Server 12 SP5-LTSS | All versions | 1.5.2-3.53.1 | | `clamav` | SUSE:Linux Enterprise Server 15 SP4-LTSS | All versions | 1.5.2-150400.13.5.1 | | `clamav` | SUSE:Linux Enterprise Server 15 SP5-LTSS | All versions | 1.5.2-150400.13.5.1 | | `clamav` | SUSE:Linux Enterprise Server 15 SP6-LTSS | All versions | 1.5.2-150600.18.25.1 | | `clamav` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 1.5.2-3.53.1 | | `clamav` | SUSE:Linux Enterprise Server for SAP Applications 15 SP4 | All versions | 1.5.2-150400.13.5.1 | | `clamav` | SUSE:Linux Enterprise Server for SAP Applications 15 SP5 | All versions | 1.5.2-150400.13.5.1 | | `clamav` | SUSE:Linux Enterprise Server for SAP Applications 15 SP6 | All versions | 1.5.2-150600.18.25.1 | | `clamav` | openSUSE:Leap 15.6 | All versions | 1.5.2-150600.18.25.1 | | `clamav` | openSUSE:Leap 16.0 | All versions | 1.5.2-160000.1.1 | | `clamav` | openSUSE:Tumbleweed | All versions | 1.5.2-1.1 | ## How do I fix CVE-2026-20031? Apply the vendor's patch. ## Is CVE-2026-20031 being exploited? There is no known exploitation of CVE-2026-20031 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-20031 and fix it if it is affected. What it is: CVE-2026-20031 is a medium-severity denial of service vulnerability in Cisco Secure Endpoint, published on 4 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-20031 in the wild and no public exploit code. Affected product: Cisco Secure Endpoint. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-20031/ (Markdown: https://insights.sbomify.com/CVE-2026-20031/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20031 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20031 - OSV: https://osv.dev/vulnerability/CVE-2026-20031 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-20031/ Summaries are generated and may contain mistakes; the official description above is the record.