CVE-2026-31974

MEDIUMCVSS 4.3/10EPSS 0.16%

Last modified

CVE-2026-31974 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. OpenProject is an open-source, web-based project management software. Prior to 17.2.0, OpenProject SMTP test endpoint (POST /admin/settings/mail_notifications) accepts arbitrary host and port values and exhibits measurable differences in response behaviour depending on whether the target IP exists and whether the port is open. EPSS estimates a 0.16% chance of exploitation in the next 30 days.

Description

OpenProject is an open-source, web-based project management software. Prior to 17.2.0, OpenProject SMTP test endpoint (POST /admin/settings/mail_notifications) accepts arbitrary host and port values and exhibits measurable differences in response behaviour depending on whether the target IP exists and whether the port is open. An attacker with access can use these timing and error distinctions to map internal hosts and identify which services/ports are reachable. Similarly, you can create webhooks in OpenProject and point them to arbitrary IPs, resulting in the same kind of SSRF issue which allows attackers to scan the internal network. This vulnerability is fixed in 17.2.0.

Metrics

CVSS 3.1
4.3/10

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

EPSS Probability
0.16%

5.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
OpenprojectOpenproject< 17.2.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-31974?
OpenProject is an open-source, web-based project management software. Prior to 17.2.0, OpenProject SMTP test endpoint (POST /admin/settings/mail_notifications) accepts arbitrary host and port values and exhibits measurable differences in response behaviour depending on whether the target IP exists and whether the port is open. An attacker with access can use these timing and error distinctions to map internal hosts and identify which services/ports are reachable. Similarly, you can create webhooks in OpenProject and point them to arbitrary IPs, resulting in the same kind of SSRF issue which allows attackers to scan the internal network. This vulnerability is fixed in 17.2.0.
How severe is CVE-2026-31974?
CVE-2026-31974 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.
How do I fix CVE-2026-31974?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-31974?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST