CVE-2026-104084

HIGH
MEDIUM Priority: 0.03 BB Relevance: 67/100
Published: 2026-10-09 Modified: 2026-10-27 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
AT: None
VC: High
VI: High
VA: High

Description

SmarterMail before build 9777 contains a privilege escalation vulnerability where JWT access and refresh tokens embed a role claim at issuance that is not revalidated against the account's current role when redeemed through POST /api/v1/auth/refresh-token. Attackers who capture a refresh token issued before an administrator demotion, or a demoted user whose session was not actively polling at the time of demotion, can replay the stale token to obtain a new access token retaining the higher-privilege role (such as DomainAdmin or SysAdmin) until natural token expiry.

Weakness Classification (1)

Bug Bounty Relevance

67 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

8.7 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

EPSS — Exploitation Probability

0.31%
Raw Score 0.003110
Percentile 24.0%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00311
2026-10-28
0.00311

Intelligence Sources

mitre ref →