CVE-2026-115586

Published Oct 23, 2026 Modified Oct 26, 2026 CWE-78

Description

virtualenv is a tool for creating isolated virtual python environments. From 21.14.9 until 21.14.13, the bash bin/activate script can copy an attacker-controlled --prompt value into PS1 without escaping dollar signs or backticks when both promptvars and POSIX mode are disabled during activation. Re-enabling promptvars, running set -o posix, or starting an interactive child bash that inherits the exported PS1 can then expand command substitution in the stored VIRTUAL_ENV_PROMPT value and execute commands as the user who activates the environment. This issue is fixed in version 21.14.13.

Is your site exposed to CVE-2026-115586?

Run a free security scan — no signup, results in seconds.

EPSS — Exploit Prediction

0.0027
Probability of exploitation
0.20%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-78 OS Command Injection

References

Frequently Asked Questions

What is CVE-2026-115586? +
virtualenv is a tool for creating isolated virtual python environments. From 21.14.9 until 21.14.13, the bash bin/activate script can copy an attacker-controlled --prompt value into PS1 without escaping dollar signs or backticks when both promptvars and POSIX mode are disabled during activation. Re-enabling promptvars, running set -o posix, or starting an interactive child bash that inherits the exported PS1 can then expand command substitution in the stored VIRTUAL_ENV_PROMPT value and execute commands as the user who activates the environment. This issue is fixed in version 21.14.13.
How do I check if I'm vulnerable to CVE-2026-115586? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

Don't wait for an exploit

Scan your website for vulnerabilities like CVE-2026-115586 — free, no signup required.

Patch and protect

Block known exploits with a web application firewall while you patch, keep your own devices clean, or test the fix on a fresh server.

Compare VPS prices →

Affiliate links: we may earn a commission, your price stays the same.