What is CVE-2026-42180?

CVE-2026-42180 is a medium-severity vulnerability in Lemmynet Lemmy, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.3/10. Published 2026-05-08.

How severe is CVE-2026-42180?

Medium severity. CVSS v3 base score is 6.3 out of 10.

SSRF in Lemmynet Lemmy

CVE-2026-42180

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend…

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.000 (11.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

Affected products

Lemmynet Lemmy — versions < 0.19.18

Weakness classification (CWE)

CWE-918 — Server-Side Request Forgery (SSRF)

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-42180?: CVE-2026-42180 is a medium-severity vulnerability in Lemmynet Lemmy, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.3/10. Published 2026-05-08.
How severe is CVE-2026-42180?: Medium severity. CVSS v3 base score is 6.3 out of 10.