# CVE-2026-123776: RRD::CGI::Image versions through 0.01 for Perl pass CGI query parameters containting "tz" to tzset(), , so a FIFO or device path blocks the CGI process

Status: published. Published: 2026-11-07. Updated: 2026-11-07.

RRD::CGI::Image versions through 0.01 for Perl pass CGI query parameters containting "tz" to tzset(), , so a FIFO or device path blocks the CGI process.

The normalize_params method sends any query key matching /tz/i to tz(), which sets $ENV{TZ} to that value, with no validation. It then calls tzset(). glibc treats a TZ value starting with / or : as a file path and opens it, so a value naming a FIFO or a blocking device stalls the process inside tzset().

## Remediation

- fix: Apply the patch. (source: CNA: CPANSec)
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: CPANSec) — https://rt.cpan.org/Ticket/Display.html?id=182627
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: CPANSec) — https://security.metacpan.org/patches/R/RRD-CGI-Image/0.01/CVE-2026-123776-r1.patch

## Affected products and versions

-  /  (RRD-CGI-Image): ≥ 0; ≤ 0.01 (affected, custom). Source: CNA: CPANSec

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-1287

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://rt.cpan.org/Ticket/Display.html?id=182627 (CNA: CPANSec; vendor-advisory, issue-tracking, patch)

- https://man7.org/linux/man-pages/man3/tzset.3.html (CNA: CPANSec; technical-description)

- https://security.metacpan.org/patches/R/RRD-CGI-Image/0.01/CVE-2026-123776-r1.patch (CNA: CPANSec; patch)

## Provenance

- CNA: CPANSec: https://www.cve.org/CVERecord?id=CVE-2026-123776; retrieved 2026-11-07; source updated 2026-11-07

Revision: 138416caa9a643b795b7695cd7fced86ab25211de3a29f3cc917e6bd1fa091fe

Canonical: https://y2.dev/cve/CVE-2026-123776

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