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Fencer Intel
medium 6.2

CVE-2026-1842 json

HyperCloud Improper Refresh Token Validation and Access Token Invalidation Allows Long-Term Unauthorized Access

published 8mo ago modified 4mo ago also EUVD-2026-8367

cvss
6.2
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

HyperCloud versions 2.3.5 through 2.6.8 improperly allowed refresh tokens to be used directly for resource access and failed to invalidate previously issued access tokens when a refresh token was used. Because refresh tokens have a significantly longer lifetime (default one year), an authenticated client could use a refresh token in place of an access token to maintain long-term access without token rotation. Additionally, old access tokens remained valid after refresh, enabling concurrent or extended use beyond intended session boundaries. This vulnerability could allow prolonged unauthorized access if a token is disclosed.

Patch / fix

  • SoftIron HyperCloud 2.6.9

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
8mo ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 4.0 6.2 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U
CNA 4.0 6.2 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/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

Affected products

  • SoftIron HyperCloud

Classification

Weakness
  • CWE-613 DEPRECATED: Insufficient Session Expiration

References

Sources

Fencer Intel 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.