CVE-2026-111442

Backdrop CMS Core Unsafe SVG Upload Allows Client‑Side Script Execution

Published Oct 16, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
Backdrop CMS Core 1.35.x before 1.35.2 and 1.34.x before 1.34.6 does not sufficiently validate uploaded SVG images to ensure they lack potentially dangerous SVG tags. SVG images can contain clickable links or executable scripting. By uploading a crafted SVG, it is possible to execute scripting in the browser when an SVG image is viewed. This issue is mitigated by the attacker needing to be able to upload SVG images, and that Backdrop embeds all uploaded SVG images within <img> tags, which prevents script from executing. The SVG must be viewed directly by its URL in order to run any embedded scripting.

Remediation

Vendor Solution

Update your site to the most recent version of Backdrop core. Download available on the Backdrop CMS 1.35.2 release page https://github.com/backdrop/backdrop/releases/tag/1.35.6 . See the update instructions https://docs.backdropcms.org/documentation/core-updates .

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Backdrop CMS Core Unsafe SVG Upload Allows Client‑Side Script Execution
Type Values Removed Values Added
Description Backdrop CMS Core 1.35.x before 1.35.2 and 1.34.x before 1.34.6 does not sufficiently validate uploaded SVG images to ensure they lack potentially dangerous SVG tags. SVG images can contain clickable links or executable scripting. By uploading a crafted SVG, it is possible to execute scripting in the browser when an SVG image is viewed. This issue is mitigated by the attacker needing to be able to upload SVG images, and that Backdrop embeds all uploaded SVG images within <img> tags, which prevents script from executing. The SVG must be viewed directly by its URL in order to run any embedded scripting.
First Time appeared Backdropcms
Backdropcms backdrop
Weaknesses CWE-79
CPEs cpe:2.3:a:backdropcms:backdrop:*:*:*:*:*:*:*:*
Vendors & Products Backdropcms
Backdropcms backdrop
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Oct 21, 2026, 2:10 AM
Reserved
Oct 16, 2026, 3:09 AM
Status
Awaiting Analysis
Published
Oct 16, 2026, 4:18 AM
Modified
Oct 21, 2026, 3:17 AM