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
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.5
Dancer2 versions before 2.2.0 for Perl do not strip CR and LF from response header names in headers_to_array
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.
- Record
CVE-2026-93711- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-113
- Updated
- 2026-11-02
EUVDEUVD-2026-84257
6.5
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.
- Record
EUVD-2026-84257- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-vp8p-vxw7-c877
6.5
Dancer2 versions before 2.2.0 for Perl do not strip CR and LF from response header names in...
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.
- Record
GHSA-vp8p-vxw7-c877- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-113
- Updated
- 2026-11-02
NVD
6.5
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.
- Record
CVE-2026-93711- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-113
- Updated
- 2026-11-02
OSV
6.5
Dancer2 versions before 2.2.0 for Perl do not strip CR and LF from response header names in headers_to_array
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.
- Record
CVE-2026-93711- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-113
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-93711
6.5
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.
- Record
DEBIAN-CVE-2026-93711- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-93711
6.5
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.
- Record
UBUNTU-CVE-2026-93711- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:12202-1 No score
perl-Dancer2-2.2.2-1.1 on GA media
These are all security issues fixed in the perl-Dancer2-2.2.2-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12202-1- Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libdancer2-perlDebian:12 |
All versions, plus listed versions 0.400001+dfsg-11.0.0+dfsg-11.1.0+dfsg-11.1.1+dfsg-11.1.2+dfsg-12.0.1-12.1.0-12.2.2-1 |
None known |
libdancer2-perlDebian:13 |
All versions, plus listed versions 1.1.2+dfsg-12.0.1-12.1.0-12.2.2-1 |
None known |
libdancer2-perlDebian:14 |
before 2.2.2-1, plus listed versions 1.1.2+dfsg-12.0.1-12.1.0-1 |
2.2.2-1 |
libdancer2-perlUbuntu:16.04:LTS |
All versions, plus listed versions 0.160003+dfsg-10.163000+dfsg-10.166001+dfsg-1 |
None known |
libdancer2-perlUbuntu:18.04:LTS |
All versions, plus listed versions 0.205000+dfsg-10.205002+dfsg-10.205002+dfsg-2 |
None known |
libdancer2-perlUbuntu:20.04:LTS |
All versions, plus listed versions 0.208001+dfsg-10.208002+dfsg-10.300000+dfsg-1 |
None known |
libdancer2-perlUbuntu:22.04:LTS |
All versions, plus listed versions 0.300005+dfsg-10.301004+dfsg-1 |
None known |
libdancer2-perlUbuntu:24.04:LTS |
All versions, plus listed versions 0.400001+dfsg-11.0.0+dfsg-11.1.0+dfsg-1 |
None known |
libdancer2-perlUbuntu:26.10 |
All versions, plus listed versions 1.1.2+dfsg-12.1.0-1 |
None known |
libdancer2-perlUbuntu:26.04:LTS |
All versions, plus listed versions 1.1.2+dfsg-1 |
None known |
perl-Dancer2openSUSE:Tumbleweed From an advisory covering 4 CVEs |
before 2.2.2-1.1 | 2.2.2-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-93711 is a medium vulnerability (CVSS 6.5) in libdancer2-perl, published September 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 31st percentile. Fixed in libdancer2-perl 2.2.2-1.
References
github.com/PerlDancer/Dancer2/issues/1822
github.com/PerlDancer/Dancer2/commit/ff89ac12af7b8899812a79e9924dfea7a5d9833b.patch
metacpan.org/release/CROMEDOME/Dancer2-2.2.0/changes
openwall.com/lists/oss-security/2026/09/22/3
nvd.nist.gov/vuln/detail/CVE-2026-93711
github.com/advisories/GHSA-vp8p-vxw7-c877
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cpan.org/modules
github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93711.json
github.com/PerlDancer/Dancer2
security-tracker.debian.org/tracker/CVE-2026-93711
ubuntu.com/security/CVE-2026-93711
cve.org/CVERecord?id=CVE-2026-93711
lists.security.metacpan.org/cve-announce/msg/43742971
suse.com/security/cve/CVE-2026-93709
suse.com/security/cve/CVE-2026-93710
suse.com/security/cve/CVE-2026-93711
suse.com/security/cve/CVE-2026-93712