CVE-2026-25561: WeKan < 8.19 Attachment Upload Object Relationship Validation Bypass

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-07 · updated 2026-07-14
Weakness: CWE-863

Description

WeKan versions prior to 8.19 contain an authorization weakness in the attachment upload API. The API does not fully validate that provided identifiers (such as boardId, cardId, swimlaneId, and listId) are consistent and refer to a coherent card/board relationship, enabling attempts to upload attachments with mismatched object relationships.

Affected products

WeKan: before 8.19 — fixed in 8.19

How to fix

Upgrade to a fixed version: WeKan 8.19. Check the vendor advisory for mitigations.

References

https://github.com/wekan/wekan/commit/1d16955b6d4f0a0282e89c2c1b0415c7597019b8
https://wekan.fi/
https://www.vulncheck.com/advisories/wekan-attachment-upload-object-relationship-validation-bypass

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