PDFME has SSRF via Unvalidated URL Fetch in getB64BasePdf When basePdf Is Attacker-Controlled

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.8 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

EPSS

• CVE-2026-82866: 0.35% estimated exploitation activity in the next 30 days; percentile 28.33 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The getB64BasePdf function in @pdfme/common fetches arbitrary URLs via fetch() without any validation when basePdf is a non-data-URI string and window is defined. An attacker who can control the basePdf field of a template (e.g., through a web application that accepts user-supplied templates) can force the server or client to make requests to arbitrary internal or external endpoints, enabling Server-Side Request Forgery (SSRF) in SSR contexts or blind request forgery in browser contexts. Details The vulnerability exists in packages/common/src/helper.ts:130-141. When getB64BasePdf receives a string that does not start with data:application/pdf;, and window is defined, it passes the string directly to fetch(): The Zod schema for basePdf in packages/common/src/schema.ts:133-135 accepts any string: The checkGenerateProps function at packages/common/src/helper.ts:279 only validates the Zod schema shape, which permits any string value. No URL allowlist, protocol restriction, or…

Published by the source

20 Mar 2026, 20:45 UTC

Last modified by the source

24 Oct 2026, 02:56 UTC

Source last checked

26 Oct 2026, 12:46 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-pgx6-7jcq-2qff

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-pgx6-7jcq-2qff

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# Patch Next advisory brief: CVE-2026-82866

Advisory: PDFME has SSRF via Unvalidated URL Fetch in `getB64BasePdf` When `basePdf` Is Attacker-Controlled
IDs: CVE-2026-82866, GHSA-pgx6-7jcq-2qff
Record: https://patchnext.com/advisories/cve-2026-82866 (revision 2, source checked 26 Oct 2026, 12:46 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @pdfme/common 5.5.10. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @pdfme/common: affected <= 5.5.9; fixed in 5.5.10

## Suggested inspection (read-only)
- `npm ls @pdfme/common --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @pdfme/common.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-pgx6-7jcq-2qff (OSV record GHSA-pgx6-7jcq-2qff lists affected ranges: npm @pdfme/common >=0 <5.5.10 (fixed))
- Verified: https://github.com/advisories/GHSA-pgx6-7jcq-2qff (GitHub-reviewed advisory GHSA-pgx6-7jcq-2qff lists affected ranges: npm @pdfme/common >=0 <=5.5.9)

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