CVE-2026-113726: virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST
Affects virtualenvSource GCVE Database
Not known to be exploited · CVSS 7.8 High : upgrade to 21.14.4 soon.
Data as of 29 Oct 2026, 14:41 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 7.8 |
|---|
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 21.14.4
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade virtualenv to 21.14.4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Bitnamivirtualenvpkg:bitnami/virtualenvOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade virtualenv to version 21.14.4 or later, where this issue is fixed. No other mitigation is required if upgrading is possible. Users of bash or zsh without PROMPT_SUBST enabled are not affected by this vulnerability.
Description
A command injection vulnerability exists in virtualenv versions prior to 21.14.4 when used with zsh shells that have PROMPT_SUBST enabled. The vulnerability arises because the environment name is assigned to the shell prompt (PS1) without proper escaping, allowing attacker-controlled input to execute commands each time the prompt is drawn. This affects virtualenv versions before 21.14.4 and is fixed in 21.14.4.
References
- github.com/pypa/virtualenv/commit/5b915367da82bd024b2a0d28d2f98007034b4aa2 (opens in a new tab)
- github.com/pypa/virtualenv/releases/tag/21.14.4 (opens in a new tab)
- github.com/pypa/virtualenv/security/advisories/GHSA-5vjq-rrrf-7h2q (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-113726 (opens in a new tab)