# CVE-2026-120651: CGI versions before 5.00 for Perl allow an infinite loop on a short request body when $DISABLE_UPLOADS is set

Status: published. Published: 2026-11-03. Updated: 2026-11-03.

CGI versions before 5.00 for Perl allow an infinite loop on a short request body when $DISABLE_UPLOADS is set.

When $CGI::PUTDATA_UPLOAD or an upload hook is set, read_postdata_putdata takes a request body that is not a form submission. With $CGI::DISABLE_UPLOADS set, it discards the body by reading until Content-Length bytes have arrived. Once a body shorter than its Content-Length runs out, every read returns 0, so the loop never ends.

A client can keep a server process spinning with one such request.

## Remediation

- fix: Upgrade to CGI 5.00 or later. (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://github.com/leejo/CGI.pm/commit/16d9f61acf8b844b7360e8d726338e3ce34dfa9f.patch
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: CPANSec) — https://github.com/leejo/CGI.pm/commit/8a78305065690461ae283fa24e5ebe4ec8a22fbc.patch

## Affected products and versions

-  /  (CGI): ≥ 0; < 5.00 (affected, custom). Source: CNA: CPANSec

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-835

## Exploit evidence

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

## References

- https://metacpan.org/release/LEEJO/CGI-4.72/source/lib/CGI.pm (CNA: CPANSec; technical-description)

- https://metacpan.org/release/LEEJO/CGI-5.00/changes (CNA: CPANSec; release-notes)

- https://github.com/leejo/CGI.pm/commit/16d9f61acf8b844b7360e8d726338e3ce34dfa9f.patch (CNA: CPANSec; patch)

- https://github.com/leejo/CGI.pm/commit/8a78305065690461ae283fa24e5ebe4ec8a22fbc.patch (CNA: CPANSec; patch)

## Provenance

- CNA: CPANSec: https://www.cve.org/CVERecord?id=CVE-2026-120651; retrieved 2026-11-04; source updated 2026-11-03

Revision: 33ad93e8c3efc546d12eaf06769677d10010bd5b17fab76d2df020b83643c1c7

Canonical: https://y2.dev/cve/CVE-2026-120651

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.