CVE-2026-48161Active Exploitation

LOWCVSS 9.3 · CRITICAL

Exploitation ongoing with high activity in latest observed window (1 mentions)

Immediate actions

  • Prioritize remediation for affected systems immediately
  • Assume compromise if assets are exposed
  • Track advisory updates for patch or workaround availability

Recommended action window: Immediate (within 24h)

NVD description

react18-use is a React 19 use hook shim. Between 2026-05-19 01:07:01 and 2026-05-19 15:20:43, the default branch contained malicious commits 7b79148d1495a2505f9277da295a98cf176f4496 through 7b79148d1495a2505f9277da295a98cf176f4496 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 2026-05-19 01:07:01 should treat the machine as compromised, rotate every credential the machine could reach, audit account activity since 2026-05-19 01:07:01, and clean local clones.

3.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-506

Priority

LOW

Exploitation

ACTIVE

PoC

NONE

Patch

NONE

Momentum

NONE

Threat summary

  • Active exploitation appears in 1 classified signals
  • 1 mentions across 1 observed day

What's happening

  • Active exploitation reported across 1 signal
  • 1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-08-11: 1Active Exploitation · 2026-08-11: 108-11
Signal classification1 categories
Active Exploitation
1100.0%
Referenced assets2 URLs
Full discourse1 post
  • CCB Alert@CCBalert
    Active Exploitation

    Warning: Supply chain attacks affected #react-tracked CVE-2026-48160 https://nvd.nist.gov/vuln/detail/CVE-2026-48160 and #react18-use CVE-2026-48161 https://nvd.nist.gov/vuln/detail/CVE-2026-48161 npm packages. Check for installed malicious packages, and if so, consider machine as compromised #Patch #Patch #Patch

    Post summary

    The warning alerts to supply chain attacks affecting the CVE-2026-48160 and CVE-2026-48161 npm packages and advises checking for malicious packages, but provides no PoC, exploit tool, or patch details.

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