SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-48160

Between 2026-05-18 19:26:36 and 2026-05-19 15:22:45, the default branch contained malicious commits 6978272a7d6ca02225cb747ea69f427512e33699 through 949f1a3d6bb1ff7d1a0dec892afd773e742627e8 that executed remote attacker-controlled code on developer…

CRITICAL 9.3EPSS 0.40%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

react-tracked provides state usage tracking with Proxies. Between 2026-05-18 19:26:36 and 2026-05-19 15:22:45, the default branch contained malicious commits 6978272a7d6ca02225cb747ea69f427512e33699 through 949f1a3d6bb1ff7d1a0dec892afd773e742627e8 that executed remote attacker-controlled code on developer machines during `npm install`. The commits were removed by force-push, but local clones, forks, and direct-SHA URLs may still contain them, and `npm install` against an affected checkout will still execute the code today. The package was not published to npm. `src/install.js` was added and wired into the `postinstall` script. It fetched a JavaScript payload from an attacker-controlled HTTPS endpoint (configurable via an environment variable), disabled TLS verification, and evaluated the response as code with `require` available. Execution was deliberately skipped on CI and cloud/serverless environments, targeting developer workstations. The second-stage payload was attacker-hosted and cannot be reconstructed. Assume full compromise of anything reachable from a Node process with the user's permissions. Those who ran `npm install` against an affected checkout on a developer machine on or after 2026-05-18 19:26:36 should treat the machine as compromised, rotate every credential the machine could reach, audit account activity** since 2026-05-18 19:26:36, and clean local clones.

CVSS 4.0
9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.40% probability · 33th percentile
CISA KEV
Not listed
Weakness
CWE-506
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.