CVE-2026-55848: MapFish Print XXE in GML layer processing

Quick answers

Is CVE-2026-55848 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-55848 being exploited in the wild.

How severe is CVE-2026-55848?

High severity, with a CVSS score of 8.6, published 28 August 2026.

Which products and versions are affected?

Mapfish Print 3.0.0–3.28.29, 3.29.0–3.30.31, 3.32.0–3.33.15, 3.34.0–4.0.4; Mapfish Print Servlet 3.29.0–3.30.31, 3.31.0–3.31.23, 3.32.0–3.33.15, 3.34.0–4.0.4; Mapfish Print-Lib 3.0.0–3.28.29, 3.29.0–3.30.31, 3.32.0–3.33.15, 3.34.0–4.0.4; org.mapfish.print:print-lib (Maven) ECOSYSTEM:introduced=3.0.0,fixed=3.28.30; and 1 more.

Is there a fix for CVE-2026-55848?

Yes. org.mapfish.print:print-lib (Maven): upgrade to 3.28.30 or later; org.mapfish.print:print-servlet (Maven): upgrade to 3.28.30 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-55848 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-55848?

Check whether you run Mapfish Print, Mapfish Print Servlet, Mapfish Print-Lib or one of the others listed 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.

How to fix

• org.mapfish.print:print-lib (Maven): upgrade to 3.28.30 or later

  # set org.mapfish.print:print-lib to 3.28.30 in your pom.xml or build.gradle

• org.mapfish.print:print-servlet (Maven): upgrade to 3.28.30 or later

  # set org.mapfish.print:print-servlet to 3.28.30 in your pom.xml or build.gradle

Technical details

The vulnerability is an XML External Entity (XXE) injection in MapFish Print's GML (Geography Markup Language) layer processing. When processing a GML layer URL in the Print API (/api/print3/print/*/buildreport.pdf), the application parses untrusted XML without properly disabling external entity resolution. An attacker can host a remote PHP script (or similar) that returns malicious XML with DOCTYPE declarations defining external entities pointing to local files (file://) or internal services (https://). By chaining this with a DTD that exfiltrates the file content through error-based XXE techniques, the attacker can read arbitrary files accessible to the MapFish process, such as /etc/passwd, Kubernetes service account tokens, TLS certificates, and configuration files. The exfiltration occurs via 404 error messages that echo the file path, allowing blind exfiltration. No authentication or user interaction is required; the attack is triggered via a single HTTP POST request to the buildreport.pdf endpoint. Patches are available in versions 3.28.30, 3.30.32, 3.31.24, 3.33.16, and 4.0.5.

Affected products

• MapFish MapFish Print 3.0.0–3.28.29, 3.29.0–3.30.31, 3.32.0–3.33.15, 3.34.0–4.0.4
• MapFish print-lib (Maven) 3.0.0–3.28.29, 3.29.0–3.30.31, 3.32.0–3.33.15, 3.34.0–4.0.4
• MapFish print-servlet (Maven) 3.29.0–3.30.31, 3.31.0–3.31.23, 3.32.0–3.33.15, 3.34.0–4.0.4

Identifiers

• CVE-2026-55848
• GHSA-5v29-34h8-v68r

Timeline

• 2026-08-28: disclosed: Publicly disclosed via GitHub Advisory GHSA-5v29-34h8-v68r
• 2026-06-22: patched: Patches released: 3.28.30, 3.30.32, 3.31.24, 3.33.16, 4.0.5

References

• https://api.github.com/users/zneek
• https://github.com/zneek
• https://api.github.com/users/zneek/gists%7B/gist_id%7D
• https://api.github.com/users/zneek/repos
• https://avatars.githubusercontent.com/u/404318?v=4
• https://api.github.com/users/zneek/events%7B/privacy%7D