CVE-2026-40280
Description
Gotenberg is an API-based document conversion tool. In versions 8.30.1 and earlier, the default private-IP deny-lists for the --webhook-deny-list and --api-download-from-deny-list flags use a case-sensitive regular expression (^https?://) to match URL schemes. Because Go's net/url.Parse() normalizes the scheme to lowercase before establishing the outbound TCP connection, an attacker can bypass the deny-list by simply capitalizing part of the URL scheme (e.g., HTTP://, HTTPS://, or Http://). This allows unauthenticated requests to reach internal network services, including private IP ranges, loopback addresses, and cloud instance metadata endpoints such as HTTP://169.254.169.254/latest/meta-data/.
This bypasses the same security control that was patched in CVE-2026-27018.
This issue has been fixed in version 8.31.0.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
github.com/gotenberg/gotenberg/v8Go | < 8.31.0 | 8.31.0 |
Affected products
3Patches
Vulnerability mechanics
References
6- github.com/gotenberg/gotenberg/commit/3f01ca18d3cc21375a1e2da4b5a3f261c8548e47nvdPatchWEB
- github.com/gotenberg/gotenberg/security/advisories/GHSA-5q7p-7jgv-ww56nvdExploitMitigationVendor AdvisoryWEB
- github.com/advisories/GHSA-5q7p-7jgv-ww56ghsaADVISORY
- github.com/advisories/GHSA-jjwv-57xh-xr6rnvdNot ApplicableADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-40280ghsaADVISORY
- github.com/gotenberg/gotenberg/releases/tag/v8.31.0ghsaWEB
News mentions
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