CVE-2026-77243 Vulnerability Analysis & Exploit Details

CVE-2026-77243
Vulnerability Scoring

8.8
/10
Severe Risk

Cybersecurity professionals consider CVE-2026-77243 an immediate threat requiring urgent mitigation.

Attack Complexity Details

  • Attack Complexity: Low
    Exploits can be performed without significant complexity or special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • Privileges Required: Low
    Some privileges are necessary to exploit the vulnerability.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2026-77243 Details

Status: Analyzed

Last updated: 🕞 29 Sep 2026, 15:32 UTC
Originally published on: 🕕 22 Sep 2026, 18:17 UTC

Time between publication and last update: 6 days

CVSS Release: version 3

CVSS3 Source

security-advisories@github.com

CVSS3 Type

Secondary

CVSS3 Vector

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

CVE-2026-77243 Vulnerability Summary

CVE-2026-77243: MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, ENABLED_TOOLS and TOOLSETS are applied when tools are listed but are not rechecked when a tools/call request is dispatched. A client that knows a hidden tool name can directly invoke excluded read, write, or delete tools despite the operator's configured least-privilege restrictions. The advisory traces the vulnerable input and processing flow through ENABLED_TOOLS, TOOLSETS, tools/list, tools/call, and _call_tool_mcp, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Assessing the Risk of CVE-2026-77243

Access Complexity Graph

The exploitability of CVE-2026-77243 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2026-77243

CVE-2026-77243 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2026-77243, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2026-77243, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: High
    Exploiting CVE-2026-77243 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: High
    CVE-2026-77243 could allow unauthorized modifications to data, potentially affecting system reliability and trust.
  • Availability: High
    CVE-2026-77243 can disrupt system operations, potentially causing complete denial of service (DoS).

CVE-2026-77243 References

External References

CWE Common Weakness Enumeration

CWE-862

CAPEC Common Attack Pattern Enumeration and Classification

  • Exploitation of Thunderbolt Protection Flaws CAPEC-665 An adversary leverages a firmware weakness within the Thunderbolt protocol, on a computing device to manipulate Thunderbolt controller firmware in order to exploit vulnerabilities in the implementation of authorization and verification schemes within Thunderbolt protection mechanisms. Upon gaining physical access to a target device, the adversary conducts high-level firmware manipulation of the victim Thunderbolt controller SPI (Serial Peripheral Interface) flash, through the use of a SPI Programing device and an external Thunderbolt device, typically as the target device is booting up. If successful, this allows the adversary to modify memory, subvert authentication mechanisms, spoof identities and content, and extract data and memory from the target device. Currently 7 major vulnerabilities exist within Thunderbolt protocol with 9 attack vectors as noted in the Execution Flow.

Vulnerable Configurations

  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.6:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.6:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.7:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.7:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.8:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.8:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.9:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.9:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.10:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.10:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.11:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.11:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.12:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.12:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.13:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.13:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.14:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.14:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.15:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.15:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.16:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.1.16:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.6:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.2.6:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.3.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.3.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.3.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.3.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.4.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.4.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.5.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.5.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.6.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.7.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.7.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.7.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.7.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.8.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.9.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.9.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.6:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.10.6:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.4:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.4:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.5:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.5:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.6:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.6:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.7:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.7:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.8:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.8:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.9:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.9:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.10:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.10:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.11:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.11:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.12:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.11.12:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.12.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.12.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.13.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.13.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.13.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.13.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.2:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.2:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.3:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.14.3:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.15.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.15.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.16.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.16.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.16.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.16.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.17.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.17.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.18.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.18.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.18.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.18.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.19.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.19.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.20.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.20.0:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.20.1:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.20.1:*:*:*:*:*:*:*
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.21.0:*:*:*:*:*:*:*
    cpe:2.3:a:mcp-atlassian:mcp_atlassian:0.21.0:*:*:*:*:*:*:*

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