---
title: "Data breach at Welyb"
description: "A security incident affected, from 1 September 2026, a technical component interacting with Welyb, a collaborative platform published by AGIRIS (ISAGRI group) and used by accounting firms to centralize documents and electronic invoicing flows with their clients. The exposure includes names, postal a"
canonical: https://inyourgeek.com/en/fuites-de-donnees/2026-09-15-welyb
type: fuite-de-donnees
author: "Sébastien Soulier"
publisher: "InYourGeek"
language: en
datePublished: 2026-09-15
dateModified: 2026-09-15
---
# Welyb

Data breach — Moderate

A security incident affected, from 1 September 2026, a technical component interacting with Welyb, a collaborative platform published by AGIRIS (ISAGRI group) and used by accounting firms to centralize documents and electronic invoicing flows with their clients. The exposure includes names, postal addresses, phone numbers, email addresses and hashed passwords, along with associated business data (company name, SIRET/SIREN, business contact details). Welyb/AGIRIS notified the affected individuals and states it neutralized the vulnerability and cut off unauthorized access upon detection. No exposure of electronic invoices or banking data has been reported at this stage.

Linking a person's identity to a specifically identifiable business via its SIRET/SIREN number facilitates targeted phishing attempts impersonating the accounting firm or tax authorities.

| Fact | Value |
| --- | --- |
| Disclosed on | September 15, 2026 |
| Incident dated | September 1, 2026 |
| Sector | Digital services |
| Country | France |
| Cause | Misconfigured database |
| Severity | Moderate |
| Status | Confirmed |

## Exposed data

- Email address
- Full name
- Phone number
- Postal address
- Employment data
- Password (hashed)

## What you can do

- Change that password — and everywhere you reused it. That is how a leak spreads to your other accounts.
- Turn on two-factor authentication on the affected accounts: a stolen password is then no longer enough.
- Expect phishing attempts quoting your name and this company. A message that knows your details is not legitimate for that reason.
- You can ask the organisation exactly what was exposed about you (right of access), and complain to the DPA if no answer comes within a month.

## Sources

- [Welyb (AGIRIS)](https://frenchbreaches.com/alertes/welyb-agiris-mu2m3x9bh33cfsst2bl) — FrenchBreaches
- [Welyb (AGIRIS) : une faille expose les données de clients de cabinets comptables](https://www.cyberattaque.org/cyberattaque-welyb-agiris-une-faille-expose-les-donnees-de-clients-de-cabinets-comptables/) — Cyberattaque.org
- [Welyb : fuite de données confirmée sur le portail des cabinets comptables](https://fuitesinfos.fr/article/2026-09-15-welyb) — Fuites Infos
- [Facturation électronique : une fuite de données touche un cador de l'écosystème comptable au pire des moments](https://www.presse-citron.net/facturation-electronique-une-fuite-de-donnees-touche-un-cador-de-lecosysteme-comptable-au-pire-des-moments/) — Presse-citron

_Entry built from the cited sources after a corroboration check, then reviewed before publication._

---

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