Medium

Stored XSS in Bludit image upload via malicious SVG

IdentifiersCVE-2026-25100CWE-79· Improper Neutralization of Input…

CVE-2026-25100 is a stored cross-site scripting vulnerability in Bludit's image upload functionality. An authenticated user with content upload privileges, including roles such as Author, Editor, or Administrator, can upload an SVG image containing attacker-controlled script payloads. Because the uploaded resource is then served and accessible without authentication, the malicious script executes in a victim's browser when the victim visits the URL of the uploaded SVG resource. Based on the provided information, all Bludit versions up to and including 3.18.2 are considered vulnerable, and CERT Polska noted that future versions might also remain vulnerable because vendor coordination stopped before a confirmed fix was documented.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an authenticated low-privilege or mid-privilege content contributor to achieve stored XSS against users who access the uploaded SVG resource. This can enable session theft, execution of arbitrary JavaScript in the victim's browser within the application's web context, unauthorized actions on behalf of the victim, credential or token capture, phishing or content injection, and potential administrative compromise if a privileged user is targeted.

Mitigation

If you can’t patch tonight, do this now.

Until a verified fix is available, disable SVG uploads entirely or restrict uploads to non-scriptable image formats. Limit upload capability to only fully trusted users, isolate user-uploaded content on a separate domain or origin, enforce restrictive Content Security Policy where feasible, and configure responses for uploaded files to reduce browser-side script execution risk. Monitoring for previously uploaded SVG files and removing untrusted content is also advisable.

Remediation

Patch, then assume compromise.

Upgrade to a vendor version that explicitly fixes CVE-2026-25100 once available. The provided content does not identify a confirmed fixed version for this CVE. Remediation should include disallowing active content in uploaded image formats, especially SVG, sanitizing SVG content server-side, validating MIME type and file content rather than extension alone, and serving user-uploaded files with headers and storage patterns that prevent script execution in the application origin.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

BluditBluditapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

3 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

3 SOURCESView more in app

cert polskaNews

Mar 1, 2026

Vulnerabilities in Bludit software | CERT Polska

A stored cross-site scripting vulnerability in Bludit's image upload functionality that allows authenticated users with content upload privileges to upload malicious SVG files that execute when accessed.

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity2