What is CVE-2020-12242?

CVE-2020-12242 is a high-severity vulnerability in Valvesoftware Source, classified under OS Command Injection. CVSS score: 7.8/10. Published 2020-04-27.

How severe is CVE-2020-12242?

High severity. CVSS v3 base score is 7.8 out of 10.

Is CVE-2020-12242 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

RCE in Valvesoftware Source

CVE-2020-12242

Valve Source allows local users to gain privileges by writing to the /tmp/hl2_relaunch file, which is later executed in the context of a different user account.

Vulnerability class: Command Injection (OS Command Injection)

Published 2020-04-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.011 (64.0th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Valvesoftware Source

Weakness classification (CWE)

CWE-78 — OS Command Injection

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

0xem.ma/cve/2020/04/28/Source-hl2-relaunch-exec.html (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2020-12242?: CVE-2020-12242 is a high-severity vulnerability in Valvesoftware Source, classified under OS Command Injection. CVSS score: 7.8/10. Published 2020-04-27.
How severe is CVE-2020-12242?: High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2020-12242 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.