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Fencer Vulns
low 3.1

CVE-2023-28847 json

Nextcloud Server missing brute force protection for passwords of password protected share links

published 2023-04-25 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-32473

cvss
3.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 55%
public exploits
0
none known

Summary

Nextcloud Server is the file server software for Nextcloud, a self-hosted productivity platform. In Nextcloud Server 24.0.0 prior to 24.0.11 and 25.0.0 prior to 25.0.5; as well as Nextcloud Server Enterprise 23.0.0 prior to 23.0.12.6, 24.0.0 prior to 24.0.11, and 25.0.0 prior to 25.0.5; an attacker is not restricted in verifying passwords of share links so they can just start brute forcing the password. Nextcloud Server 24.0.11 and 25.0.5 and Nextcloud Enterprise Server 23.0.12.6, 24.0.11, and 25.0.5 contain a fix for this issue. No known workarounds are available.

Patch / fix

  • nextcloud nextcloud_server 23.0.12.6, 24.0.11, 25.0.5

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-28847 updated cvss 3.1

nextcloud: brute forcing password verification

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
21 mo ago

Exploit prediction

0.77% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/1894653 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • nextcloud security-advisories

Classification

Weakness
  • CWE-307 Improper Restriction of Excessive Authentication Attempts

References

Sources

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.