CVE-2024-52521 | Nextcloud Server has a potential hash collision for background jobs could skip queuing them

Nextcloud Server is a self hosted personal cloud system. MD5 hashes were used to check background jobs for their uniqueness. This increased the chances of a background job with arguments falsely being identified as already existing and not be queued for execution. By changing the Hash to SHA256 the probability was heavily decreased. It is recommended that the Nextcloud Server is upgraded to 28.0.10, 29.0.7 or 30.0.0.

Published: 2024-11-15 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-52521 is rated Low Risk (20.6/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.39%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-52521

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.77% 0.39% -0.38%
2 2026-03-04 0.24% 0.77% +0.54%
3 2026-03-01 — 0.24% —

Full EPSS history (29 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-52521

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.6 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 1.2 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2024-52521

Affected software / configurations for CVE-2024-52521

Vendor Product Version Raw CPE
nextcloud nextcloud_server >= 28.0.0, < 28.0.10 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*
nextcloud nextcloud_server >= 28.0.0, < 28.0.10 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*
nextcloud nextcloud_server >= 29.0.0, < 29.0.7 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*
nextcloud nextcloud_server >= 29.0.0, < 29.0.7 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*

References for CVE-2024-52521

cvelogic Threat Intelligence