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NVD / CVE Program· CNA VulnCheck

CVE-2026-101056: Cloudreve before 4.16.1 Authentication Bypass via Cached Context Hint

Noroxi assessment

Priority: Monitor (action score 27/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.19% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: cloudreve cloudreve 4.16.1.

Low priority for now. Upgrade to cloudreve cloudreve 4.16.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Cloudreve before 4.16.1 fails to revalidate share access when restoring cached navigator state from a context_hint UUID. Attackers who previously had valid share access can replay the cached hint to generate signed file URLs for up to 300 seconds after the share is deleted, expires, or reaches zero remaining downloads.

MediumCVSS 6.9 · v4.0—No exploit Fix available
Published
Sep 27, 2026
Updated
Oct 8, 2026
EPSS
0.1% · 9th percentile

Report tools

JSON

Action score

27

Monitor

Low priority for now.

CVSS
27 / 40 · 6.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
6.9
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-101056

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • cloudreve cloudreve

    • 4.16.1not affected
    • before 4.16.1affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gogithub.com/cloudreve/Cloudrevefrom 0—
Gogithub.com/cloudreve/Cloudreve/v3from 0—
Gogithub.com/cloudreve/Cloudreve/v4from 0—
Gogithub.com/cloudreve/Cloudreve/v4up to and including 4.0.0-20260606032813-26b6b1044b02—

Same product

cloudreve: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-25726Cloudreve is vulnerable to Account Takeover via Weak Cryptographic Token Generation (Insecure PRNG Seeding)
    39Monitor
  • CVE-2026-54560Cloudreve: OAuth access tokens bypass scope enforcement due to missing client_id claim
    30Monitor
  • CVE-2026-77633Cloudreve: Storage-quota TOCTOU race allows quota bypass and storage-based denial of service
    28Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-79913Sep 22, 2026 · Cloudreve: SSRF guard bypass: checkIP does not decode IPv6-transition wrappers (NAT64, IPv4-compatible, 6to4) reaching internal and cloud-metadata addresses
    26Monitor
  • ← EarlierCVE-2026-101051Sep 27, 2026 · Cloudreve before 4.16.1 Path Traversal via Remote Download
    9Monitor
  • ← EarlierCVE-2026-101048Sep 27, 2026 · Cloudreve before 4.17.0 SSRF via Admin.Read OAuth scope
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
cloudreve cloudreve4.16.1Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-5456074 days apartCloudreve: OAuth access tokens bypass scope enforcement due to missing client_id claim
    30Monitor
  • CVE-2026-5550258 days apartCloudreve: OAuth Admin.Read scope can update OneDrive storage policy credentials
    28Monitor
  • CVE-2026-5456374 days apartCloudreve: Path Traversal / Broken Access Control in Cloudreve WebDAV (`/dav`) — scoped DAV credential escapes its configured account root
    28Monitor
  • CVE-2026-6232358 days apartCloudreve: Unauthorized file write via WOPI view sessions whose access token secret is ignored
    25Monitor
  • CVE-2026-1010480 days apartCloudreve before 4.17.0 SSRF via Admin.Read OAuth scope
    21Monitor
  • CVE-2026-5549958 days apartCloudreve: Broken access control in file event stream leaks activity events for unshared siblings to single-file share recipients
    17Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2026-799135 days apartCloudreve: SSRF guard bypass: checkIP does not decode IPv6-transition wrappers (NAT64, IPv4-compatible, 6to4) reaching internal and cloud-metadata addresses
    26Monitor
  • CVE-2026-1010480 days apartCloudreve before 4.17.0 SSRF via Admin.Read OAuth scope
    21Monitor
  • CVE-2026-5549558 days apartCloudreve: Path Traversal in WOPI PUT_RELATIVE Allows Arbitrary File Creation in Owner Account
    17Monitor
  • CVE-2026-1010510 days apartCloudreve before 4.16.1 Path Traversal via Remote Download
    9Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-863 · Incorrect Authorization

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓
  2. SSVC exploitation— → poc

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records