---
id: "CVE-2026-62860"
kind: "vulnerability"
aliases: ["CVE-2026-62860"]
title: "Picsou: login timing reveals which usernames exist on the server"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["java", "package", "picsou", "self-hosted", "spring"]
not_affected_if: ["not-network-reachable", "version-1.0.8-or-later"]
published_at: "2026-10-30T21:17:14+00:00"
first_seen_at: "2026-10-30T21:25:53+00:00"
updated_at: "2026-10-30T21:26:56+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-62860", "first_seen_at": "2026-10-30T21:25:53+00:00"}]
---

# Picsou: login timing reveals which usernames exist on the server

Picsou's login endpoint answers faster for unknown usernames than for existing ones, so latency measurements reveal valid accounts. An attacker gets a list of usernames to target with credential guessing, but not the passwords or account data.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the Picsou version in the deployed repository or release tag; versions before `1.0.8` are affected.
- Look for the timing difference in `backend/src/main/java/com/picsou/controller/AuthController.java`: `login()` throws `BadCredentialsException` before `passwordEncoder.matches(...)` runs for unknown usernames.

## Fix

- Picsou: move to `1.0.8`.

## Timeline

- 2026-10-30T21:25:53+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-62860

## From the sources

Picsou is a self-hosted personal finance dashboard. In the affected login implementation, the `/api/auth/login` endpoint reveals whether a username exists through a timing discrepancy. In `backend/src/main/java/com/picsou/controller/AuthController.java`, `AuthController.login()` throws `BadCredentialsException` immediately for an unknown username, before `passwordEncoder.matches(...)`, whereas an existing username with an incorrect password incurs the `bcrypt` comparison cost. Both cases return the same generic `HTTP 401` response, but repeated latency measurements disclose valid usernames without credentials. Login rate limiting, a small user population, and deployments inaccessible from outside the local network limit practical exposure; the weakness does not itself read or modify account data, though enumerated usernames can assist credential stuffing or brute-force attacks. This issue is fixed in repository release 1.0.8.

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