CriticalCVE-2025-30066

    tj-actions/changed-files GitHub Action Embedded Malicious Code Vulnerability (CVE-2025-30066)

    Published Last modified In CISA KEV since Sources: OSV, pwn.watch, CVE.org

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    What is affected, what to do

    tj-actions changed-files before 46 allows remote attackers to discover secrets by reading actions logs. (The tags v1 through v45.0.7 were affected on 2025-03-14 and 2025-03-15 because they were modified by a threat actor to point at commit 0e58ed8, which contained malicious updateFeatures code.)

    The vulnerability is being actively exploited; treat it as a priority. Update changed-files GitHub Action to version 46. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • changed-files GitHub Action lt 1..46
    Fixed in
    • changed-files GitHub Action 46

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    8.6

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    8.6

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: OSV, pwn.watch, CVE.org

    72.1 %

    EPSS score

    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.

    Source: FIRST EPSS, percentile 99.43

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    230.17 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    actively exploitedSource: VulnCheck KEV (opens in a new tab), CIRCL Sightings How we classify
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    8.6 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.6
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    72.1 %
    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    99.43
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    CISA assessment (SSVC)
    Exploitation: active · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 22 March 2025
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-506

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This is a software supply-chain compromise: widely used version tags were silently repointed at malicious code. Exploitation needed no authentication or user interaction, since anyone able to read a public repository's logs could harvest secrets that reach into cloud accounts, package registries and other repositories. Exploitation likelihood is very high, and CISA does not flag known ransomware use. The deciding question is whether any affected runs executed on 14/15 March. If they did, handle it as a confirmed credential exposure with immediate rotation and an NIS2 reporting assessment. If not, the version upgrade plus SHA pinning is the structural fix.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory every usage: Search all orgs and repos, e.g. GitHub code search org:<ORG> "tj-actions/changed-files" path:.github/workflows or locally grep -rn "tj-actions/changed-files" .github/workflows/. Include forks, internal mirrors and GitHub Enterprise Server instances.
      • Identify runs in the compromise window: List every workflow run on 2025-03-14 and 2025-03-15 that referenced any tag from v1 to v45.0.7, or commit 0e58ed8 directly. Treat every secret available to those jobs as exposed.
      • Rotate and revoke secrets: Rotate everything those workflows could access: AWS access keys, GitHub PATs and app tokens, npm/PyPI tokens, private RSA/SSH keys, and cloud and database credentials. Public repositories come first, because their logs were world-readable.
      • Delete logs from affected runs: Remove them via the UI or gh api -X DELETE repos/<OWNER>/<REPO>/actions/runs/<RUN_ID>/logs. Take a forensic copy into restricted storage first.
      • Upgrade to the fixed release: Move to changed-files v46 or later and reference it by full 40-character commit SHA, not by tag. Alternatively, disable the step until reviewed or replace it with an internally vetted equivalent.

    2. Runbook step 2

      Mitigation layers

      • Supply-chain configuration: Mandate SHA pinning for all third-party actions and ban tag or branch references. Enforce this with a CI linter (e.g. zizmor, or actionlint with a custom rule) as a required status check under branch protection.
      • Org policy: Set Actions permissions to "Allow select actions" and maintain an explicit allowlist of SHA-pinned actions. Enable Dependabot for the github-actions ecosystem so that updates arrive as reviewed PRs.
      • IAM / least privilege: Replace long-lived cloud keys with OIDC federation (e.g. AWS AssumeRoleWithWebIdentity, with the trust policy scoped to repo:<ORG>/<REPO>:ref:refs/heads/main). Restrict GITHUB_TOKEN via permissions: to contents: read. Scope secrets to the jobs that need them, and use Environments with required reviewers.
      • Network (runner egress): Apply allowlist-based egress filtering on self-hosted runners and block gist.githubusercontent.com and other raw-content hosts the build does not need. On GitHub-hosted runners, add egress monitoring such as Harden-Runner in audit or block mode.
      • Endpoint hardening (self-hosted): Run ephemeral runners (one job per VM or container). Remove passwordless sudo from the runner user so that untrusted steps cannot read Runner.Worker process memory. Set kernel.yama.ptrace_scope=2.
      • Log exposure: Review workflow-log visibility on public repositories, and keep ACTIONS_STEP_DEBUG disabled by default.

    3. Runbook step 3

      Detection rules

      • Workflow logs: Grep changed-files step output for unusually long Base64 blobs; secrets were written to the log double Base64-encoded. Pattern: regex [A-Za-z0-9+/=]{200,} in runs from 2025-03-14/15. Decode hits twice to confirm exactly which secrets leaked.
      • Cloud audit (CloudTrail): Hunt for use of potentially leaked keys from unfamiliar IPs or ASNs after 2025-03-14. SPL sketch: index=cloudtrail userIdentity.accessKeyId IN (<leaked_keys>) | stats values(sourceIPAddress) values(eventName) by userIdentity.accessKeyId. Focus on GetCallerIdentity, ListBuckets and CreateAccessKey.
      • GitHub audit log: Look for token use from atypical IPs, new deploy keys, repo.add_member, protected_branch.destroy, and package.published events outside normal pipelines. Also check npm publish history for unexpected versions.
      • Runner telemetry (auditd/EDR): Flag the process chain Runner.Worker → node → bash/curl → python3 (via sudo), and any reads of /proc/<pid>/mem or /proc/<pid>/maps belonging to the runner process. auditd starting point: -a always,exit -F arch=b64 -S open,openat -F dir=/proc -F success=1 -k proc_mem_read, filtered for mem and maps.
      • Network (Zeek/Suricata/DNS): Alert on DNS or TLS SNI for gist.githubusercontent.com from CI segments. Suricata sketch: alert tls $CI_NET any -> any any (tls.sni; content:"gist.githubusercontent.com"; msg:"CI runner fetches gist content";).

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    tj-actions changed-files before 46 allows remote attackers to discover secrets by reading actions logs. (The tags v1 through v45.0.7 were affected on 2025-03-14 and 2025-03-15 because they were modified by a threat actor to point at commit 0e58ed8, which contained malicious updateFeatures code.)

    Source: OSV (Open Source Vulnerabilities), pwn.watch, NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    tj-actionschanged-files
    • 1 – < 46
    • ≤ 45.0.7
    • 46
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-506Embedded Malicious Code

      Class

      The product contains code that appears to be malicious in nature.

      Entry at MITRE CWE-506

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited

    References & sources

    • github.comGHSA-mw4p-6x4p-x5m5: tj-actions changed-files through 45.0.7 allows remote attackers to discover secretsweb, pwn-watch
    • NVD (NIST)NVD: CVE-2025-30066advisory, pwn-watch
    • github.comespressif/arduino-esp32/issues/11127web
    • github.commodal-labs/modal-examples/issues/1100web
    • github.comtj-actions/changed-files/issues/2463web
    • github.comtj-actions/changed-files/issues/2464web
    • github.comtj-actions/changed-files/issues/2477web
    • github.comchains-project/maven-lockfile/pull/1111web
    • github.comrackerlabs/genestack/pull/903web
    • sysdig.comblog/detecting-and-mitigating-the-tj-actions-changed-files-supp…web
    • web.archive.orgweb/20250315060250/https://github.com/tj-actions/changed-files/…web
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2025-30066web, government-resource
    • cisa.govnews-events/alerts/2025/03/18/supply-chain-compromise-third-par…web
    • stepsecurity.ioHarden-Runner detection: tj-actions/changed-files action is compromisedweb, pwn-watch
    • stream.securitypost/github-action-supply-chain-attack-exposes-secrets-what-you…web
    • sweet.securityblog/cve-2025-30066-tj-actions-supply-chain-attackweb
    • wiz.ioblog/github-action-tj-actions-changed-files-supply-chain-attack…web
    • semgrep.devblog/2025/popular-github-action-tj-actionschanged-files-is-comp…web
    • news.ycombinator.comitem?id=43368870web
    • news.ycombinator.comitem?id=43367987web

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    One NVD translation into another language is hidden.

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