CVE-2026-40893: Gotenberg arbitrary file manipulation via ExifTool tag bypass

CVE-2026-40893 · Severity: high · CVSS 8.2 · Published 2026-05-14

Gotenberg is a service used to convert various document formats into PDF files. A security flaw allows unauthenticated remote attackers to bypass safety restrictions and rename, move, or change the permissions of files on the server. This could lead to service disruptions or allow an attacker to place malicious files in shared storage areas used by other applications.

Technologies: github.com/gotenberg/gotenberg/v7 (Go), github.com/gotenberg/gotenberg/v8 (Go), Gotenberg. Vendors: Go, Gotenberg.

Quick answers

Is CVE-2026-40893 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-40893 being exploited in the wild.
How severe is CVE-2026-40893?
High severity, with a CVSS score of 8.2, published 14 May 2026.
Which products and versions are affected?
github.com/gotenberg/gotenberg/v7 (Go) SEMVER:introduced=0; github.com/gotenberg/gotenberg/v8 (Go) <= 8.30.1, SEMVER:introduced=0, SEMVER:introduced=0,last_affected=8.30.1; Gotenberg < 8.31.0, <= 8.30.1.
Is there a fix for CVE-2026-40893?
A patch was published on 2026-05-14: Fixed in version 8.31.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-40893 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-40893?
Check whether you run github.com/gotenberg/gotenberg/v7 (Go), github.com/gotenberg/gotenberg/v8 (Go) or Gotenberg at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

Gotenberg utilizes ExifTool to process document metadata but fails to properly sanitize group-prefixed tag names. While the application attempts to block dangerous tags like 'FileName' and 'Directory', it uses a simple string comparison that does not account for ExifTool's support for group prefixes (e.g., 'System:FileName'). An attacker can bypass the blocklist by prepending 'System:' to restricted tags or by using the 'FilePermissions' tag, which was entirely omitted from the blocklist. This allows for arbitrary file manipulation (move/rename/chmod) within the container environment. The vulnerability is reachable via any endpoint that accepts the 'metadata' field, such as PDF conversion or merging routes.

Affected products

  • Gotenberg Gotenberg < 8.31.0

Identifiers

  • CVE-2026-40893
  • GHSA-62p3-hvxx-fxg4
  • GO-2026-5162

Timeline

  • 2026-05-01: advisory: GitHub Security Advisory published
  • 2026-05-14: disclosed: CVE published to NVD
  • 2026-05-14: patched: Fixed in version 8.31.0

References

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