TI-2026-75143 Aliases CVE-2026-111442 GHSA-gcjx-3jpq-qx2p

Backdrop CMS SVG upload validation flaw enables cross-site scripting

LOW 24CWE-79Published 2026-10-16 · Updated 2026-10-21

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Cross-site scripting
Confidentiality · integrity · availability: None · Low · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

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. An attacker who can upload SVG images can craft one that runs script in the browser when the file is viewed directly by its URL. Backdrop embeds uploaded SVG images in img tags, which prevents the script from executing in normal page views. CVSS 4.0 scores the issue 5.3 (MEDIUM), and CISA has not added it to KEV.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00234 14th percentileScored 2026-11-07

Fix Fixed Backdrop (BackdropCMS): 1.35.2, 1.34.6

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
backdropcms	Backdrop	1.35.0 to before 1.35.2; 1.34.0 to before 1.34.6	1.35.2, 1.34.6	Patch available	CNA

Backdrop Vendorbackdropcms Affected 1.35.0 to before 1.35.2; 1.34.0 to before 1.34.6 Fixed in 1.35.2, 1.34.6 Patch available CNA

Remediation

Upgrade to 1.35.2 on the 1.35.x branch or to 1.34.6 on the 1.34.x branch.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Fix · CNA Backdrop (BackdropCMS) Fixed in 1.35.2, 1.34.6

Timeline

2026-10-16 Threatist record created from CVE-2026-111442
2026-10-16 Alias added: GHSA-gcjx-3jpq-qx2p
2026-10-21 CISA SSVC decision points changed

References

Other 1

https://backdropcms.org/security/backdrop-sa-core-2026-007

TI-2019-08480 jQuery before 3.4.0, as used in Drupal, Backdrop CMS, and other products, mishandles… CVSS 3.1MEDIUM 6.1
TI-2025-39465 Host Header Injection vulnerability in Backdrop CMS 1.32.1 allows attackers to manipulate… CVSS 3.1MEDIUM 6.1
TI-2023-14781 A stored Cross-site scripting (XSS) issue in Text Editors and Formats in Backdrop CMS… CVSS 3.1MEDIUM 4.8
TI-2022-20387 Backdrop CMS version 1.23.0 was discovered to contain a stored cross-site scripting (XSS) vulnerability via 'Comment.' . CVSS 3.1MEDIUM 4.8
TI-2022-20386 Backdrop CMS version 1.23.0 was discovered to contain a stored cross-site scripting (XSS)… CVSS 3.1MEDIUM 4.8
TI-2022-20385 Backdrop CMS version 1.23.0 was discovered to contain a stored cross-site scripting (XSS)… CVSS 3.1MEDIUM 4.8

See all 34 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences