Nextcloud: Missing permission check for from submissions

published 2026-06-01 5 mo ago modified 2026-07-22 3 mo ago also EUVD-2026-33679

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits: 0; none known

Nextcloud is an open source content collaboration platform. Prior to version 5.2.6, a missing permissions check allowed users to request reading form submissions of other users. This issue has been patched in version 5.2.6.

Patch / fix

fixed in 1 links 1

nextcloud forms 5.2.6

github.com/nextcloud/forms#3269 pull request

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-06-01)

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

nextcloud security-advisories

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-862 Missing Authorization

References

Sources

CVE List CVE-2026-45267
NVD CVE-2026-45267

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary