CVE-2026-54163
secure_headers: CSP directive injection via sandbox, plugin_types, and report_to when given untrusted input
Description
secure_headers manages application of security headers with many safe defaults. Prior to 7.3.0, secure_headers builds the Content-Security-Policy value by stitching directives with ; separators, and build_sandbox_list_directive, build_media_type_list_directive, and build_report_to_directive interpolate caller-supplied strings without scrubbing ;, \r, or \n. When untrusted input reaches SecureHeaders.override_content_security_policy_directives or append APIs for :sandbox, :plugin_types, or :report_to, an attacker can inject a CSP directive such as script-src 'unsafe-inline' * before the legitimate script-src, enabling XSS reachability through these sinks or CSP report exfiltration. This issue is fixed in version 7.3.0.
INFO
Published Date :
July 17, 2026, 9:17 p.m.
Last Modified :
July 17, 2026, 9:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-54163
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
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update secure_headers to version 7.3.0 or later.
- Scrub input for special characters before interpolation.
- Sanitize all user-supplied strings for directives.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54163.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54163 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-2026-54163
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-2026-54163 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54163 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]
Jul. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'github', 'product': 'secure_headers', 'versions': [{'status': 'affected', 'version': '< 7.3.0'}]}] Added Description secure_headers manages application of security headers with many safe defaults. Prior to 7.3.0, secure_headers builds the Content-Security-Policy value by stitching directives with ; separators, and build_sandbox_list_directive, build_media_type_list_directive, and build_report_to_directive interpolate caller-supplied strings without scrubbing ;, \r, or \n. When untrusted input reaches SecureHeaders.override_content_security_policy_directives or append APIs for :sandbox, :plugin_types, or :report_to, an attacker can inject a CSP directive such as script-src 'unsafe-inline' * before the legitimate script-src, enabling XSS reachability through these sinks or CSP report exfiltration. This issue is fixed in version 7.3.0. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N Added CWE CWE-79 Added CWE CWE-113 Added Reference https://github.com/github/secure_headers/commit/286a79dea80c6a9be4ca93e0f284c923cf77e539 Added Reference https://github.com/github/secure_headers/releases/tag/v7.3.0 Added Reference https://github.com/github/secure_headers/security/advisories/GHSA-rqq5-2gf9-4w4q