CVE-2026-42589

CVE-2026-42589 is a critical-severity vulnerability in Thecodingmachine Gotenberg with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Description

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.31.0, Gotenberg's /forms/pdfengines/metadata/write HTTP endpoint accepts a JSON metadata object and passes its keys directly to ExifTool via the go-exiftool library. No validation is performed on key characters. A \n embedded in a JSON key splits the ExifTool stdin stream into a new argument line, allowing an attacker to inject arbitrary ExifTool flags — including -if, which evaluates Perl expressions. This achieves unauthenticated OS command execution in a single HTTP request. The response is HTTP 200 with a valid PDF, making the attack transparent to basic monitoring. This vulnerability is fixed in 8.31.0.

Frequently asked questions

What is CVE-2026-42589?
Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.31.0, Gotenberg's /forms/pdfengines/metadata/write HTTP endpoint accepts a JSON metadata object and passes its keys directly to ExifTool via the go-exiftool library. No validation is performed on key characters. A \n embedded in a JSON key splits the ExifTool stdin stream into a new argument line, allowing an attacker to inject arbitrary ExifTool flags — including -if, which evaluates Perl expressions. This achieves unauthenticated OS command execution in a single HTTP request. The response is HTTP 200 with a valid PDF, making the attack transparent to basic monitoring. This vulnerability is fixed in 8.31.0.
How severe is CVE-2026-42589?
CVE-2026-42589 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-42589 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42589?
CVE-2026-42589 affects Thecodingmachine Gotenberg. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-42589?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-42589 have an EU (EUVD) identifier?
Yes. CVE-2026-42589 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30311.
When was CVE-2026-42589 published?
CVE-2026-42589 was published on 2026-05-14 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Thecodingmachine Gotenberg

All CVEs affecting Thecodingmachine Gotenberg →

Other CWE-78 (OS Command Injection) vulnerabilities

Browse all CWE-78 (OS Command Injection) vulnerabilities →