What is CVE-2026-41243?

CVE-2026-41243 is a medium-severity vulnerability in Siemvk Openlearn, classified under Improper Access Control. CVSS score: 5.4/10. Published 2026-04-23.

How severe is CVE-2026-41243?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Vulnerability in Siemvk Openlearn

CVE-2026-41243

OpenLearn is open-source educational forum software. Prior to commit 844b2a40a69d0c4911580fe501923f0b391313ab, when `safeMode` is enabled, unapproved forum posts are hidden from the public list, but the direct post-read procedure still returns the full post to anyone with the post UUID. Commit 844b2a40a69d0c4911580fe501923f0b391313ab fixes the issue.

Published 2026-04-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (14.9th percentile), scored 2026-10-08.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 14.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Siemvk Openlearn — versions < 844b2a40a69d0c4911580fe501923f0b391313ab

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

github.com/siemvk/OpenLearn/security/advisories/GHSA-4rv3-hfh6-vqvm (Exploit, Vendor Advisory)
github.com/siemvk/OpenLearn/commit/844b2a40a69d0c4911580fe501923f0b391313ab (Patch)

Frequently asked questions

What is CVE-2026-41243?: CVE-2026-41243 is a medium-severity vulnerability in Siemvk Openlearn, classified under Improper Access Control. CVSS score: 5.4/10. Published 2026-04-23.
How severe is CVE-2026-41243?: Medium severity. CVSS v3 base score is 5.4 out of 10.