6.5
MEDIUM CVSS 2.0
CVE-2026-5559
AntaresMugisho PyBlade AST Validation sandbox.py _is_safe_ast special elements used in a template engine
Description

A vulnerability has been found in AntaresMugisho PyBlade 0.1.8-alpha/0.1.9-alpha. The affected element is the function _is_safe_ast of the file sandbox.py of the component AST Validation. Such manipulation leads to improper neutralization of special elements used in a template engine. The attack may be performed from remote. The exploit has been disclosed to the public and may be used. The project was informed of the problem early through an issue report but has not responded yet.

INFO

Published Date :

April 5, 2026, 11:16 a.m.

Last Modified :

April 5, 2026, 11:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-5559 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 MEDIUM [email protected]
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM [email protected]
Solution
Sanitize template engine inputs to prevent improper neutralization of special elements.
  • Update PyBlade to a patched version once available.
  • Validate and sanitize all inputs to the template engine.
  • Review AST validation logic for improper neutralization flaws.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-5559 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-5559 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-5559 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-5559 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Apr. 05, 2026

    Action Type Old Value New Value
    Added Description A vulnerability has been found in AntaresMugisho PyBlade 0.1.8-alpha/0.1.9-alpha. The affected element is the function _is_safe_ast of the file sandbox.py of the component AST Validation. Such manipulation leads to improper neutralization of special elements used in a template engine. The attack may be performed from remote. The exploit has been disclosed to the public and may be used. The project was informed of the problem early through an issue report but has not responded yet.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/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
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
    Added CVSS V2 (AV:N/AC:L/Au:S/C:P/I:P/A:P)
    Added CWE CWE-791
    Added CWE CWE-1336
    Added Reference https://github.com/AntaresMugisho/PyBlade/
    Added Reference https://github.com/AntaresMugisho/PyBlade/issues/1
    Added Reference https://github.com/AntaresMugisho/PyBlade/issues/1#issue-4086730906
    Added Reference https://vuldb.com/submit/782904
    Added Reference https://vuldb.com/vuln/355329
    Added Reference https://vuldb.com/vuln/355329/cti
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.