CPANSec Discloses Legacy Dancer Session-ID Validation Flaw
Tech GuruQuick Answer
Identify Dancer deployments before 1.3400 and the session engine in use. Upgrade to 1.3400 or later, test session-ID validation and retain deployment evidence.
Confirm Scope And Apply The Supported Remediation
What to do now: Locate Dancer in Perl application environments and containers; record the loaded framework version, session backend, service owner and cookie handling. Trace whether client-controlled session identifiers reach file, cache or query operations without backend validation. The advisory does not establish the same impact for every session engine. Use an approved Dancer release at or above 1.3400, rebuild deployment artifacts and restart long-running application processes as needed. Test session creation, login continuity, expiry and rejection of invalid identifiers in staging. Retain module versions, backend configuration, test results and deployment records.
Last verified: 2026-11-15 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.
Scope And Authority
| Product scope | Dancer Perl web framework and configured session engines |
|---|---|
| Advisory | CVE-2015-10149 |
| CVE | CVE-2015-10149 |
| Authoritative release date | 2026-11-14 20:13 UTC — CPANSec announcement, published to minute precision. The Dancer 1.3400 software fix dates to 2018-06-15. |
| Authority revision date | No separate advisory revision date is supplied. |
| Affected versions | Dancer before 1.3400. Impact depends on a session engine using an unchecked client-supplied session identifier in a file path, cache command or query. |
| Fixed version | Dancer 1.3400 or later |
| CVSS base score | Not provided by the authority |
| CVSS severity | Not provided by the authority |
| Exploitation status | CPANSec does not confirm exploitation in the wild.; no exploitation claim is inferred. |
What Changed
The November 14 CPANSec advisory documents unchecked session-cookie identifiers reaching the session engine, potentially enabling path traversal or injection. The stable 1.3400 fix was released in June 2018; this is a new advisory for a legacy flaw.
What To Validate Now
- Inventory. Locate Dancer in Perl application environments and containers; record the loaded framework version, session backend, service owner and cookie handling.
- Establish applicability. Trace whether client-controlled session identifiers reach file, cache or query operations without backend validation. The advisory does not establish the same impact for every session engine.
- Remediate. Use an approved Dancer release at or above 1.3400, rebuild deployment artifacts and restart long-running application processes as needed.
- Validate. Test session creation, login continuity, expiry and rejection of invalid identifiers in staging. Retain module versions, backend configuration, test results and deployment records.
- Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.
Operational Cautions
The advisory records an earlier validation change that was reverted for Dancer::Session::Cookie compatibility. Test the actual session backend before rollout and plan for session invalidation; the 1.3400 fix date is not November 2026.
Evidence To Retain
- Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
- UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
- Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.
Related TechGeeks Resources
Authoritative References
Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.
