CVE-2026-77268Public exploitHinoki check available

OAuth token theft via permissive fallback files

Published Sep 22, 2026 · Updated Sep 22, 2026

Incorrect file permissions in sooperset MCP Atlassian before 0.22.0 allow local users to read stored OAuth access and refresh tokens. OAuthConfig._save_tokens_to_file() creates ~/.mcp-atlassian and oauth-<client_id>.json through default-mode operations instead of enforcing owner-only access. Exploitation requires local filesystem access to a traversable home directory and grants the victim's Jira and Confluence API permissions.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Incorrect file permissions in sooperset MCP Atlassian before 0.22.0 allow local users to read stored OAuth access and refresh tokens. OAuthConfig._save_tokens_to_file() creates ~/.mcp-atlassian and oauth-<client_id>.json through default-mode operations instead of enforcing owner-only access. Exploitation requires local filesystem access to a traversable home directory and grants the victim's Jira and Confluence API permissions.

The record

CVE
CVE-2026-77268
Published
Sep 22, 2026
Updated
Sep 22, 2026
Vendor
sooperset
Product
MCP Atlassian
Classifications
CWE-732, T1552.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.22.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

sooperset · MCP Atlassianversion=< 0.22.0

Published CVSS scores

5.5GitHubCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-732Incorrect Permission Assignment for Critical Resource
T1552.001Credentials In Files

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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