CVE-2023-28999

mediumpriority · track · 26OT risk · elevatedEPSS 0.007 · 52 %ileDEEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.68% (52nd) EPSS

CVSS 6.4 · medium

Is it mine?

14 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · osv · cert_bund

EPSS · scored 2026-10-27

Nextcloud is an open-source productivity platform. In Nextcloud Desktop client 3.0.0 until 3.8.0, Nextcloud Android app 3.13.0 until 3.25.0, and Nextcloud iOS app 3.0.5 until 4.8.0, a malicious server administrator can gain full access to an end-to-end encrypted folder. They can decrypt files, recover the folder structure and add new files. This issue is fixed in Nextcloud Desktop 3.8.0, Nextcloud Android 3.25.0, and Nextcloud iOS 4.8.0. No known workarounds are available.

cvss

Technical severity, 0–10. One row per scoring source.

6.9

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.16.4mediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:Lprimary · NVD / NIST USexploitability 0.9 · impact 5.5

v3.16.9mediumCVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:Lsecondary · ENISA EU

v3.16.9mediumCVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:Lsecondary · security-advisories@github.comexploitability 0.4 · impact 6

v3.15.9mediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:L/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-311USprimaryCWE-325US

affected products (14)

Products and version ranges known to be affected.

Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Nextcloud Nextcloud <3.25.0 Androidall versionscert_bundDE
Nextcloud Nextcloud <3.8.0 Desktopall versionscert_bundDE
Nextcloud Nextcloud <4.8.0 iOSall versionscert_bundDE
nextcloud nextcloud< 3.25.0 Androidcert_bundDE
nextcloud nextcloud< 3.8.0 Desktopcert_bundDE
nextcloud nextcloud< 4.8.0 iOScert_bundDE
nextcloud security-advisories3.0.0, → 3.8.0enisa_euvdEU
nextcloud security-advisories3.0.5, → 4.8.0enisa_euvdEU
nextcloud security-advisories3.13.0, → 3.25.0enisa_euvdEU
nextcloud desktop3.0.0 → 3.8.0nvdUScpe:2.3:a:nextcloud:desktop:*:*:*:*:*:*:*:*
nextcloud nextcloud3.0.5 → 4.8.0nvdUScpe:2.3:a:nextcloud:nextcloud:*:*:*:*:*:*:*:*
nextcloud nextcloud3.13.0 → 3.25.0nvdUScpe:2.3:a:nextcloud:nextcloud:*:*:*:*:*:*:*:*
Bitnami nextcloud3.0.5 → 4.8.0osvUSpkg:bitnami/nextcloud

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-0847Nextcloud: Mehrere Schwachstellen ermöglichen Manipulation von DateienDeutsch2023-04-04csaf · cert_bundDE
Ein lokaler Angreifer kann mehrere Schwachstellen in Nextcloud ausnutzen, um Dateien zu manipulieren.
BIT-nextcloud-2023-28999Nextcloud: Lack of authenticity of metadata keys allows a malicious server to gain access to E2EE folders2026-07-12vendor · osvUS
Nextcloud is an open-source productivity platform. In Nextcloud Desktop client 3.0.0 until 3.8.0, Nextcloud Android app 3.13.0 until 3.25.0, and Nextcloud iOS app 3.0.5 until 4.8.0, a malicious server administrator can gain full access to an end-to-end encrypted folder. They can decrypt files, recover the folder structure and add new files. This issue is fixed in Nextcloud Desktop 3.8.0, Nextcloud Android 3.25.0, and Nextcloud iOS 4.8.0. No known workarounds are available.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv cert_bund nvd NVD CVE.org MITRE

published 2023-04-04modified 2026-06-17

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+763 more

references (10)

External citations — patches, advisories, analysis.

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