SEPTEMBER 18, 2026
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Case File

CVE-2026-54739

MEDIUM · CVSS 6.9 EPSS 0.43% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-19 · Last synced 2026-09-18

CyberRota Analysis

AI-Generated

Lemmy's login endpoint prior to version 0.19.19 and 1.0.0-beta.1 is vulnerable to an information disclosure issue, where it reveals whether a username or email exists based on the type of error returned during login attempts. This discrepancy allows unauthenticated attackers to confirm valid accounts, potentially facilitating targeted credential attacks or social engineering. Organizations using affected versions should prioritize updating to the latest releases to mitigate this risk.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-54739
Severity
MEDIUM
CVSS
6.9
EPSS
0.43%

Original NVD Description

Lemmy is a link aggregator and forum for the fediverse. Prior to 0.19.19 and 1.0.0-beta.1, Lemmy's login endpoint in crates/api/api/src/local_user/login.rs returns different errors depending on whether the username_or_email value exists. LocalUserView::find_by_email_or_name propagates a NotFound response for an unknown account, while an existing account with a wrong password returns LemmyErrorType::IncorrectLogin. This observable response discrepancy, including HTTP 404 for a nonexistent account and HTTP 400 for an incorrect password on an existing account, allows an unauthenticated attacker to confirm registered usernames or email addresses and use the results for targeted credential attacks or social engineering. This issue is fixed in versions 0.19.19 and 1.0.0-beta.1.