CVE-2023-28833

highpriority · track · 35EPSS 0.008 · 55 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.76% (55th) EPSS

CVSS 8.8 · high

Is it mine?

11 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

Nextcloud server is an open source home cloud implementation. In affected versions admins of a server were able to upload a logo or a favicon and to provided a file name which was not restricted and could overwrite files in the appdata directory. Administrators may have access to overwrite these files by other means but this method could be exploited by tricking an admin into uploading a maliciously named file. It is recommended that the Nextcloud Server is upgraded to 24.0.10 or 25.0.4. Users unable to upgrade should avoid ingesting logo files from untrusted sources.

cvss

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

8.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–high · 2.4–8.8

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 5.9

v3.18.8highAV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.12.4lowCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:Lsecondary · ENISA EU

v3.12.4lowCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:Lsecondary · security-advisories@github.comexploitability 0.9 · impact 1.4

v3.18.1highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

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

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-434USprimaryCWE-22USCWE-22USCWE-434US

affected products (11)

Products and version ranges known to be affected.

nextcloud security-advisories≤ < 24.0.10enisa_euvdEU
nextcloud security-advisories25.0.0, → 25.0.4enisa_euvdEU
Nextcloud GmbH Nextcloud Enterprise Server23.00 → 23.0.14fstec_bduRU
Nextcloud GmbH Nextcloud Enterprise Server24.0.0 → 24.0.10fstec_bduRU
Nextcloud GmbH Nextcloud Enterprise Server25.0.0 → 25.0.4fstec_bduRU
Nextcloud GmbH Nextcloud Server24.0.0 → 24.0.10fstec_bduRU
Nextcloud GmbH Nextcloud Server25.0.0 → 25.0.4fstec_bduRU
ООО «Ред Софт» РЕД ОС≤ 7.3fstec_bduRU
nextcloud nextcloud server23.0.0 → 23.0.14nvdUScpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*
nextcloud nextcloud server24.0.0 → 24.0.10nvdUScpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*
nextcloud nextcloud server25.0.0 → 25.0.4nvdUScpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2023-03-30modified 2026-06-17

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references (7)

External citations — patches, advisories, analysis.

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