3.8

CVE-2026-77637: cloudreve Missing Authorization

CVSS: 3.8v3.1LowDeferred
AliasesGHSA-w89x-c962-c44gGO-2026-6576
Published 22-09-2026Last modified 22-09-2026
Open JSON

Vulnerability summary

CVE-2026-77637 is a low (CVSS 3.8) Missing Authorization vulnerability in cloudreve. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 24.3% of scored vulnerabilities.

Overall risk
15/100
0100
Low · default modelHow is this calculated?
CVSS score
3.8/10
010
Low · v3.1 (CVE.org)
EPSS score
0.33%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 22-09-2026
    PublishedVulnerability first disclosed.
  2. 22-09-2026
    Last modifiedVulnerability information updated.

Description

Cloudreve is a self-hosted file management and sharing system. Prior to 4.18.0, tool.GET("wopi") and tool.POST("mail") in routers/router.go inherit ScopeAdminRead but omit the RequiredScopes(types.ScopeAdminWrite) middleware applied to neighboring state-changing admin tool routes. An OAuth application or API key limited to Admin.Read can therefore probe configured WOPI service endpoints and send arbitrary test email through the server SMTP configuration, exceeding the token's intended read-only authorization boundary. This issue is fixed in version 4.18.0.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.33%

Chance of exploitation in the next 30 days

Percentile

24%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

23-09-202621-10-2026
EPSS score
0.33%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Github.com/cloudreve/Cloudreve2 products
  • v3All versions (No fix recorded)
  • v4< 4.0.0-20260715070110-bce08f88e9d8
Cloudreve1 product
Github.com/cloudreve1 product
  • CloudreveAll versions (No fix recorded)

3 vendors · 4 products

References

5 links