tj-actions changed-files GitHub Action: vulnerability flaw under attack

What is affected

tj-actions changed-files GitHub Action is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.

tj-actions/changed-files GitHub Action contains an embedded malicious code vulnerability that allows a remote attacker to discover secrets by reading Github Actions Workflow Logs. These secrets may include, but are not limited to, valid AWS access keys, GitHub personal access tokens (PATs), npm tokens, and private RSA keys.

What an attacker can do

This is a vulnerability flaw. It lets an attacker misuse the product in a way its maker did not intend. CISA lists it because attackers are confirmed to be using it against real systems.

How it is reached

Over the internet or network

Access the attacker needs

No account needed

Does the victim have to do something?

No, works without the victim doing anything

What to do

1. At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
2. If you administer tj-actions changed-files GitHub Action at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
3. If the product is past its support date and no fix exists, take it off the internet or retire it.

Apply mitigations as set forth in the CISA instructions linked below. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Vendor advisories and fixes

• github.comgithub.com/tj-actions/changed-files/blob/45fb12d7a8bedb4da42342e52fe054c6c2c3fd73/README.m

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on March 18, 2025, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by April 8, 2025, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.

The EPSS model estimates a 72% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 99.4% of all scored vulnerabilities.

Its CVSS severity score is 8.6 out of 10 (high), as recorded in the US National Vulnerability Database.

Technical 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.)