Retrospective for 2026-05-12, compiled on 27 October 2026. The date identifies the day being analysed; source publication and revision dates are recorded below.
What this advisory changes in your environment
The starting point is CERTFR-2026-AVI-0569, published on 2026-05-12. Its scope includes Nextcloud Enterprise Server, Collectives app, User OIDC, Calendar, End-to-End Encryption, Nextcloud Server, Android Files. Reported consequences are data integrity compromise, impact requiring vendor clarification, security control bypass, loss of confidentiality. These statements apply to the advisory’s scope; they do not assign every consequence to every product or CVE.
This case contains 19 version entries; CVE identifier count: 10. Track remediation by component: a successful overall update does not demonstrate that Nextcloud Enterprise Server and Android Files each received their respective fix.
Products and versions to examine
- Reference
- CERTFR-2026-AVI-0569
- Source first published
- 2026-05-12
- Latest source revision available for this day
- 2026-05-12
- Named components
- Nextcloud Enterprise Server, Collectives app, User OIDC, Calendar, End-to-End Encryption, Nextcloud Server, Android Files
- CVE identifiers
- CVE-2026-45282, CVE-2026-45157, CVE-2026-45154, CVE-2026-45284, CVE-2026-45286, CVE-2026-45159, CVE-2026-45285, CVE-2026-45155, CVE-2026-45156, CVE-2026-45153
| Component | Published condition |
|---|---|
| Nextcloud Enterprise Server | 31.0.x : < 31.0.14.5 |
| Collectives app | < 4.3.0 |
| Nextcloud Enterprise Server | 27.0.x : < 27.1.11.5 |
| End-to-End Encryption | 1.17.x : < 1.17.1 |
| Nextcloud Server | 33.0.x : < 33.0.3 |
| End-to-End Encryption | 1.15.x : < 1.15.4 |
| Android Files | 33.x : < 33.1.0 |
| Nextcloud Enterprise Server | 30.0.x : < 30.0.17.9 |
| Nextcloud Server | 32.0.x : < 32.0.9 |
| End-to-End Encryption | 1.16.x : < 1.16.3 |
| Nextcloud Enterprise Server | 29.0.x : < 29.0.16.16 |
| Nextcloud Enterprise Server | 26.0.x : < 26.0.13.26 |
| Nextcloud Enterprise Server | 28.0.x : < 28.0.14.17 |
| Calendar | 6.2.x : < 6.2.3 |
| Nextcloud Enterprise Server | 33.0.x : < 33.0.3 |
| Nextcloud Enterprise Server | 32.0.x : < 32.0.9 |
| End-to-End Encryption | 1.18.x : < 1.18.1 |
For Nextcloud Enterprise Server, the published condition is “31.0.x : < 31.0.14.5”. Compare the version actually loaded with that condition within its own release branch. A fix installed on another edition of Nextcloud Enterprise Server does not close this case.
Mechanism and prerequisites
A security bypass challenges a trust boundary. Verify server-side authorisation decisions and alternative paths; hiding an interface is not an access restriction.
For CERTFR-2026-AVI-0569, the retained documents do not provide a suitably dated primary CVE record to establish this case’s prerequisites. Required authentication, user interaction and active exploitation therefore remain unestablished here; they are not inferred from Nextcloud Enterprise Server or the risk category alone.
Choose the appropriate intervention
- Locate Nextcloud Enterprise Server instances, running releases and service owners. Record condition 31.0.x : < 31.0.14.5 in the ticket alongside reference CERTFR-2026-AVI-0569.
- Compare the installed branch with the vendor’s Nextcloud Enterprise Server release notes. Prepare the package for that branch and a dependent-service test, retaining the pre-change state.
- After changing Nextcloud Enterprise Server, capture the loaded version again and verify the workflow below. Any exception needs an owner, an exposure-reduction measure and an expiry date.
Verify the fix in a real workflow
Validation scenario to adapt for Nextcloud Enterprise Server: On a test copy of Nextcloud Enterprise Server, compare ordinary and administrative accounts on the same workflow. Check creation, reading and modification of a synthetic object, then inspect submitted-content rendering without exposing real data. This is a proposed defensive check, not a claim that testing was performed against third-party systems.
Limit of case CERTFR-2026-AVI-0569: this analysis replaces neither vendor prerequisites nor investigation of your logs. Only documented versions are reproduced; no attack date or victim is invented.
Questions specific to this case
Which condition should be checked for Nextcloud Enterprise Server?
Advisory CERTFR-2026-AVI-0569 states: Nextcloud Enterprise Server — 31.0.x : < 31.0.14.5. Check the edition and running release; do not extend the published boundary to branches absent from the advisory.
Why not use one fix for Nextcloud Enterprise Server and Android Files?
CERTFR-2026-AVI-0569 distinguishes these components within a scope containing 19 entries. Match each branch to its own update documentation and functional check.
What is still needed to assess Nextcloud Enterprise Server exposure?
For Nextcloud Enterprise Server, establish the running version, the path to the component and process permissions. The sources retained for CERTFR-2026-AVI-0569 do not establish every prerequisite or active exploitation.
Sources and related reading
- CERT-FR · CERTFR-2026-AVI-0569
- Vendor and remediation · github.com
- Vendor and remediation · github.com
- Vendor and remediation · github.com
- Vendor and remediation · github.com
Practical guide : Software inventory: prepare for end of support
Explore the decision addressed in this case
Complete source advisory inventory
The article table may be an extract. These lists contain every affected-system entry and CVE in the specified advisory revision. They are not an inventory of your assets and do not map every CVE to every product.
Official source · CERTFR-2026-AVI-0569
Advisory revision : · Checked on :
Affected systems · 19
Original French wording is retained to avoid ambiguous translations of version conditions.
- Nextcloud Enterprise Server versions 31.0.x antérieures à 31.0.14.5
- Collectives app versions antérieures à 4.3.0
- User OIDC versions postérieures ou égales à 0.3.0 et antérieures à 8.4.0
- Nextcloud Enterprise Server versions 27.0.x antérieures à 27.1.11.5
- Calendar versions postérieures ou égales à 5.5.13 et antérieures à 5.5.17
- End-to-End Encryption versions 1.17.x antérieures à 1.17.1
- Nextcloud Server versions 33.0.x antérieures à 33.0.3
- End-to-End Encryption versions 1.15.x antérieures à 1.15.4
- Android Files versions 33.x antérieures à 33.1.0
- Nextcloud Enterprise Server versions 30.0.x antérieures à 30.0.17.9
- Nextcloud Server versions 32.0.x antérieures à 32.0.9
- End-to-End Encryption versions 1.16.x antérieures à 1.16.3
- Nextcloud Enterprise Server versions 29.0.x antérieures à 29.0.16.16
- Nextcloud Enterprise Server versions 26.0.x antérieures à 26.0.13.26
- Nextcloud Enterprise Server versions 28.0.x antérieures à 28.0.14.17
- Calendar versions 6.2.x antérieures à 6.2.3
- Nextcloud Enterprise Server versions 33.0.x antérieures à 33.0.3
- Nextcloud Enterprise Server versions 32.0.x antérieures à 32.0.9
- End-to-End Encryption versions 1.18.x antérieures à 1.18.1