Security readout for executives and security teams
Plain-English summary
A pull request could change Claude Code Action's MCP configuration before version 1.0.74. If the action ran on that PR with privileged credentials, attacker-supplied configuration could run code on the GitHub Actions runner and expose available workflow secrets.
Executive priority
Prioritize remediation for repositories that run Claude Code Action on external pull requests with secrets or broad GitHub token permissions. The likely business risk is credential exposure and runner-level code execution, not broad internet exploitation.
Technical view
Before 1.0.74, the action checked out the PR head, loaded .mcp.json from the workspace, and enabled all project MCP servers. A malicious PR could influence MCP server execution under the workflow context. Version 1.0.74 restores .claude/ and .mcp.json from the base branch before the CLI runs.
Likely exposure
Exposure is limited to GitHub repositories using anthropics/claude-code-action versions below 1.0.74 where the action runs on pull requests or issues with secrets or privileged tokens available.
Exploitation context
The source bundle does not show known active exploitation or KEV listing. Exploitation requires an attacker-created pull request and invocation of the Claude action under conditions that expose useful workflow secrets or permissions.
Researcher notes
Key conditions are version below 1.0.74, PR head checkout, project MCP settings loaded from the workspace, and automatic enablement of project MCP servers. Evidence supports RCE and secret exfiltration impact, but not observed exploitation.
Mitigation direction
- Upgrade anthropics/claude-code-action to version 1.0.74 or later.
- Review vendor advisory and release notes for any newer guidance.
- Restrict workflow secrets and token permissions for pull request contexts.
- Avoid running privileged automation on untrusted pull request content.
- Review affected repositories for unexpected MCP configuration changes.
Validation and detection
- Inventory GitHub workflows using anthropics/claude-code-action.
- Confirm all references resolve to version 1.0.74 or later.
- Check whether workflows expose secrets during pull request handling.
- Review recent pull requests for modified .mcp.json or .claude/ content.
- Validate workflow permissions are least privilege for PR events.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-200: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-78: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-47751 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N——GitHub_MVulnerability scoring details
Base CVSS 4.0 score
5.3MediumVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/anthropics/claude-code-action/security/advisories/GHSA-8q5r-mmjf-575qCVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/anthropics/claude-code-action/pull/1066CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/anthropics/claude-code-action/commit/9ddce40de8c1ab71fb6303a125fdad0968dc1312CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/anthropics/claude-code-action/releases/tag/v1.0.74CVE reference, GitHub_M · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.