CVE-2026-93711
Dancer2 versions before 2.2.0 for Perl do not strip CR and LF from response header names in headers_to_array
Description
Dancer2 versions before 2.2.0 for Perl do not strip CR and LF from response header names in headers_to_array. The routine removes CR and LF from each header value but not from the name. A name carrying them therefore reaches the PSGI server intact. A server that does not validate keys writes it to the wire, so the bytes after the CRLF arrive as their own header line. The application has to derive the header name from request data, not just the value. An attacker who controls that data adds their own headers and splits the response.
INFO
Published Date :
Sept. 22, 2026, 1:16 a.m.
Last Modified :
Sept. 22, 2026, 1:16 a.m.
Remotely Exploit :
No
Source :
9b29abf9-4ab0-4765-b253-1875cd9b441e
Affected Products
The following products are affected by CVE-2026-93711
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
Solution
- Update Dancer2 to version 2.2.0 or later.
- Validate header names from request data.
- Sanitize header names before processing.
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-2026-93711.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-93711 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-2026-93711
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-2026-93711 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-93711 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.
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New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e
Sep. 22, 2026
Action Type Old Value New Value Added Description Dancer2 versions before 2.2.0 for Perl do not strip CR and LF from response header names in headers_to_array. The routine removes CR and LF from each header value but not from the name. A name carrying them therefore reaches the PSGI server intact. A server that does not validate keys writes it to the wire, so the bytes after the CRLF arrive as their own header line. The application has to derive the header name from request data, not just the value. An attacker who controls that data adds their own headers and splits the response. Added CWE CWE-113 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93711.json">CVE-2026-93711</a> Added Reference https://github.com/PerlDancer/Dancer2/commit/ff89ac12af7b8899812a79e9924dfea7a5d9833b.patch Added Reference https://github.com/PerlDancer/Dancer2/issues/1822 Added Reference https://metacpan.org/release/CROMEDOME/Dancer2-2.2.0/changes