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TI-2025-35156 Aliases CVE-2025-55735

flaskBlog Stored XSS Vulnerability

Priority MEDIUM 57CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
None · None · None
Fix status
No fix listed

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

Summary

flaskBlog is a blog app built with Flask. In 2.8.0 and earlier, when creating a post, there's no validation of the content of the post stored in the variable "postContent". The vulnerability arises when displaying the content of the post using the | safe filter, that tells the engine to not escape the rendered content. This can lead to a stored XSS inside the content of the post. The code that causes the problem is in template/routes.html.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00211 11th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
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

VendorProductAffected versionsFixed inStatusSource
DogukanUrkerFlaskBlogup to 2.8.0—No fix listedCNA
  • FlaskBlog VendorDogukanUrker Affected up to 2.8.0 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:dogukanurker:flaskblog:*:*:*:*:*:*:*:*up to 2.8.0VulnerableDogukanUrker
  • cpe:2.3:a:dogukanurker:flaskblog:*:*:*:*:*:*:*:* Versions up to 2.8.0 Vulnerable ·DogukanUrker

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-55735

References

Exploit 1

  • TI-2025-35157 flaskBlog allows arbitrary privilege escalation CVSS 4.0CRITICAL 9.3
  • TI-2025-20720 Incorrect access control in laskBlog v2.6.1 allows attackers to access all usernames via a crafted input. CVSS 3.1CRITICAL 9.1
  • TI-2025-35158 flaskBlog arbitrary comment delete CVSS 4.0MEDIUM 6.9
  • TI-2025-35155 flaskBlo Authorization Bypass CVSS 4.0MEDIUM 6.9
  • TI-2025-20717 An arbitrary file deletion vulnerability in the /post/{postTitle} component of flaskBlog… CVSS 3.1MEDIUM 6.5
  • TI-2024-14987 User profile page vulnerable to Cross Site Scripting (XSS) in flaskBlog CVSS 3.1MEDIUM 6.5
See all 9 →

Sources

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