CVE-2026-42084 | OpenC3 COSMOS: Hijacked session token can be used to reset password for persistence

Exp

OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. Prior to versions 6.10.5 and 7.0.0-rc3, the OpenC3 password change functionality allows a user to change their password without providing the old password, by accepting a valid session token instead. In assumed breach scenarios, this behaviour can be exploited by an attacker who has already obtained a valid session token, to gain persistence in hijacked account (including admin) and prevent legitimate users from accessing the account. This issue has been patched in versions 6.10.5 and 7.0.0-rc3.

Published: 2026-05-04 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42084 is rated Exploit Available (55.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.30%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-42084

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-42084

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.30% +0.28%
2 2026-05-05 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42084

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 5.2 [email protected]

Weakness enumeration for CVE-2026-42084

GitHub Security Advisory for CVE-2026-42084

GHSA-wgx6-g857-jjf7 · Severity: high · Ecosystem: rubygems — OpenC3 COSMOS: Hijacked session token can be used to reset password for persistence

Affected software / configurations for CVE-2026-42084

Vendor Product Version Raw CPE
openc3 cosmos < 6.10.5 cpe:2.3:a:openc3:cosmos:*:*:*:*:open_source:*:*:*
openc3 cosmos 7.0.0 cpe:2.3:a:openc3:cosmos:7.0.0:rc1:*:*:open_source:*:*:*
openc3 cosmos 7.0.0 cpe:2.3:a:openc3:cosmos:7.0.0:rc2:*:*:open_source:*:*:*

References for CVE-2026-42084

cvelogic Threat Intelligence