Which versions of Pybbs are affected by CVE-2025-8550?

Organizations using atjiu pybbs should be aware of moderate risk from CVE-2025-8550, a cross-site scripting vulnerability rated CVSS 4.8.. A patch is available.

Is there a public PoC exploit available for CVE-2025-8550?

Yes, a public proof-of-concept exploit is available for CVE-2025-8550. Prioritise patching immediately. EPSS: 0.3%.

How to fix or mitigate CVE-2025-8550?

During next maintenance window: Identify affected systems running atjiu pybbs and apply vendor patches when convenient. Verify Content-Security-Policy and output encoding.

Pybbs CVE-2025-8550

Q: What is the CVSS score of CVE-2025-8550?

CVE-2025-8550 has a CVSS 4.0 base score of 1.9 (Low). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.3%.

LOW

Cross-site Scripting (XSS) (CWE-79)

2025-08-05 cna@vuldb.com

XSS Pybbs Pybbs Project

1.9

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

1.9 LOW

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

Scope

Lifecycle Timeline

Severity Changed

Apr 29, 2026 - 01:11 NVD

MEDIUM LOW

CVSS changed

Apr 29, 2026 - 01:11 NVD

4.8 (MEDIUM) 1.9 (LOW)

Analysis Generated

Mar 28, 2026 - 19:05 vuln.today

Patch released

Mar 28, 2026 - 19:05 nvd

Patch available

PoC Detected

Sep 04, 2025 - 15:37 vuln.today

Public exploit code

CVE Published

Aug 05, 2025 - 07:15 nvd

MEDIUM 4.8

DescriptionCVE.org

A vulnerability was found in atjiu pybbs up to 6.0.0. It has been declared as problematic. Affected by this vulnerability is an unknown functionality of the file /admin/topic/list. The manipulation of the argument Username leads to cross site scripting. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The patch is named 2fe4a51afbce0068c291bc1818bbc8f7f3b01a22. It is recommended to apply a patch to fix this issue.

AnalysisAI

A vulnerability was found in atjiu pybbs up to 6.0.0. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.

Technical ContextAI

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. A vulnerability was found in atjiu pybbs up to 6.0.0. It has been declared as problematic. Affected by this vulnerability is an unknown functionality of the file /admin/topic/list. The manipulation of the argument Username leads to cross site scripting. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The patch is named 2fe4a51afbce0068c291bc1818bbc8f7f3b01a22. It is recommended to apply a patch to fix this issue. Affected products include: Pybbs Project Pybbs. Version information: up to 6.0.0..

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.