6.4

CVE-2026-53521: Nezha Monitoring: Stored future DDNS profile ID allows unauthorized use of another user's DDNS profile context

Deferred
AliasesGHSA-39g2-8x68-pmx8GO-2026-5826
Published 12-06-2026Last modified 15-06-2026

Vulnerability summary

CVE-2026-53521 is a medium (CVSS 6.4) Incorrect Authorization vulnerability in nezhahq nezha. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 22.8% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.4/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.31%
0%100%
Low · +0.08 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1

Timeline

  1. 12-06-2026
    PublishedVulnerability first disclosed.
  2. 15-06-2026
    Last modifiedVulnerability information updated.

Description

Nezha Monitoring is a self-hostable, lightweight, servers and websites monitoring and O&M tool. From version 2.0.14 to before version 2.1.0, PATCH /server/{id} accepts and persists nonexistent ddns_profiles IDs for a member-owned server. If another user later creates a DDNS profile with one of those IDs, the DDNS worker resolves the stored ID and dispatches an update using the other user's DDNS profile configuration in the context of the attacker's server. This issue has been patched in version 2.1.0.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.31%

Chance of exploitation in the next 30 days

Percentile

23%

Versus all other CVEs

30-day change

Increase +0.08 pp

From 0.23% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Github.com/nezhahq1 product
  • nezha≥ 2.0.14, < 2.1.0 | All versions (No fix recorded)
Nezhahq1 product

2 vendors · 2 products

References

3 links