PinchTab has a Blind SSRF via browser-side redirect bypass in /download URL validation

Exploitation

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

CVSS

5.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

EPSS

• CVE-2026-33081: 0.29% estimated exploitation activity in the next 30 days; percentile 22.05 (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.

The /download endpoint validates only the initial URL provided by the user using validateDownloadURL() to prevent requests to internal or private network addresses. Exploitation requires \security.allowDownload=true, which is disabled by default. However, pages loaded by the embedded Chromium browser can trigger additional browser-side requests (for example, JavaScript redirects, navigations, or resource requests) after the initial validation step. Because the validation is only applied to the initial URL and not to subsequent browser-issued request targets, an attacker-controlled page can cause the browser to issue requests to internal network services reachable from the PinchTab host. This results in a blind Server-Side Request Forgery (SSRF) condition in which internal-only services may be accessed and state-changing endpoints may be triggered without returning the response body to the attacker. Steps to Reproduce: Environment Setup Target: PinchTab server (tested on v0.8.x,…

Published by the source

18 Mar 2026, 16:34 UTC

Last modified by the source

20 Mar 2026, 21:28 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-qwxp-6qf9-wr4m

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# Patch Next advisory brief: CVE-2026-33081

Advisory: PinchTab has a Blind SSRF via browser-side redirect bypass in /download URL validation
IDs: CVE-2026-33081, GHSA-qwxp-6qf9-wr4m
Record: https://patchnext.com/advisories/cve-2026-33081 (revision 1, source checked 26 Oct 2026, 15:18 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/pinchtab/pinchtab 0.8.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/pinchtab/pinchtab: affected <= 0.8.2; fixed in 0.8.3

## Suggested inspection (read-only)
- Go github.com/pinchtab/pinchtab: check the installed version with your package manager.

## 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 github.com/pinchtab/pinchtab.
- 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://github.com/advisories/GHSA-qwxp-6qf9-wr4m (GitHub-reviewed advisory GHSA-qwxp-6qf9-wr4m lists affected ranges: Go github.com/pinchtab/pinchtab >=0 <=0.8.2)

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