CVE-2026-45157

CVE-2026-45157 is a medium-severity vulnerability with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-284.

Key facts

Description

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, when a malicious user has access to a file share of a user, they could use this share token to also access the chunking upload directly and see temporary part files during on going uploads. It is recommended that the Nextcloud Server is upgraded to 32.0.9 or 33.0.3. It is recommended that the Nextcloud Enterprise Server is upgraded to 26.0.13.26, 27.1.11.25, 28.0.14.17, 29.0.16.16, 30.0.17.9, 31.0.14.5, 32.0.9 or 33.0.3

Frequently asked questions

What is CVE-2026-45157?
Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, when a malicious user has access to a file share of a user, they could use this share token to also access the chunking upload directly and see temporary part files during on going uploads. It is recommended that the Nextcloud Server is upgraded to 32.0.9 or 33.0.3. It is recommended that the Nextcloud Enterprise Server is upgraded to 26.0.13.26, 27.1.11.25, 28.0.14.17, 29.0.16.16, 30.0.17.9, 31.0.14.5, 32.0.9 or 33.0.3
How severe is CVE-2026-45157?
CVE-2026-45157 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2026-45157 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-45157?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-45157 have an EU (EUVD) identifier?
Yes. CVE-2026-45157 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33676.
When was CVE-2026-45157 published?
CVE-2026-45157 was published on 2026-06-01 and last updated on 2026-06-17.

References

Other CWE-284 (Improper Access Control) vulnerabilities

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