CVE-2025-55735: flaskBlog is a blog app built with Flask

Q: How do I fix CVE-2025-55735?

flaskblog: upgrade to newer than 2.8.0. Exact commands for each OS are on this page.

Q: Is CVE-2025-55735 being exploited?

CVE-2025-55735 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-55735 affect?

CVE-2025-55735 affects flaskblog. Severity is medium (CVSS 5.4). 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 us

Q: How urgent is CVE-2025-55735?

Priority 27/100. Public exploit reference

Routine

MEDIUM 5.4UPGRADE

CVE-2025-55735 is a medium-severity flaw (CVSS 5.4) affecting flaskblog. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.2% (top 89%)
CISA exploited list	No
Weakness	CWE-79, CWE-807
Published	2025-08-19
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: dogukanurker

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-08-19 19:15 UTCPublished CVE record published
2026-06-17 09:42 UTCUpdated Record last modified

dogukanurker flaskblog UPGRADE

Affected: <= 2.8.0

Fixed in: newer than 2.8.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy flaskblog || rpm -q flaskblog || flaskblog --version

2. UPGRADE to newer than 2.8.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade flaskblog

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade flaskblog

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-55735?

flaskblog: upgrade to newer than 2.8.0. Exact commands for each OS are on this page.

Is CVE-2025-55735 being exploited?

CVE-2025-55735 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-55735 affect?

CVE-2025-55735 affects flaskblog. Severity is medium (CVSS 5.4). 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 us

How urgent is CVE-2025-55735?

Priority 27/100. Public exploit reference

Software pages

Flask vulnerabilities

Related CVEs

CVE-2025-55737 MEDIUM 6.5 UPGRADE flaskBlog is a blog app built with Flask
CVE-2025-55736 MEDIUM 6.5 UPGRADE flaskBlog is a blog app built with Flask
CVE-2025-55734 MEDIUM 6.5 UPGRADE flaskBlog is a blog app built with Flask
CVE-2025-53631 MEDIUM 5.4 UPGRADE flaskBlog is a blog app built with Flask
CVE-2025-28104 CRITICAL 9.1 DOWNGRADE Incorrect access control in laskBlog v2.6.1 allows attackers to access all usernames via a crafted input.

References

← Back to latest CVEs