Security readout for executives and security teams
Plain-English summary
Nextcloud Mail versions before 1.12.2 could let one authenticated system user access or affect another user's mail attachments because ownership checks were missing. The issue affects confidentiality and integrity, not availability, and the vendor recommends upgrading the Mail app.
Executive priority
Treat as a moderate-priority patching item. It is not described as exploited, but it can expose private attachments between authenticated users, creating privacy and trust risk.
Technical view
The flaw is a missing user account ownership check in Nextcloud Mail attachment update or delete tasks. CVSS 3.1 is 5.4: network attack vector, low complexity, low privileges required, no user interaction, with low confidentiality and integrity impact.
Likely exposure
Exposure is most likely on multi-user Nextcloud deployments running the Mail app earlier than 1.12.2, especially where users handle mail attachments through the app.
Exploitation context
The source bundle does not report active exploitation, and KEV is false. The CVSS vector indicates exploitation would require an authenticated low-privilege user over the network, without user interaction.
Researcher notes
Evidence is limited to the advisory, CVE data, and linked fix references. The bug class is an authorization or ownership validation failure, mapped in the bundle to CWE-287. No exploit details should be inferred from the sources.
Mitigation direction
- Upgrade the Nextcloud Mail app to 1.12.2 or later.
- Do not rely on a workaround; the advisory says none is available.
- Prioritize shared or multi-user Nextcloud environments first.
- Check Nextcloud vendor guidance or support for any later updates.
Validation and detection
- Inventory Nextcloud instances and installed Mail app versions.
- Confirm every affected instance runs Mail app 1.12.2 or later.
- Review available logs for unexpected mail attachment access or modification.
- Verify no operational process depends on an undocumented workaround.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-287: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2022-31131 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N2.82.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xhv7-5mhv-299jCVE reference · x_refsource_CONFIRM
- https://github.com/nextcloud/mail/pull/6600CVE reference · x_refsource_MISC
- https://github.com/nextcloud/mail/pull/6600/commits/6dd2527be8d4f6788b449c8a8f5577628b990605CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Authentication
Improper Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.