CVE-2026-22702: Hatch · virtualenv Has TOCTOU Vulnerabilities in Directory Creation
Affects hatchSource GCVE Database
Not known to be exploited · CVSS 4.5 Medium : upgrade to 1.16.2_2 or 1.6.2 when convenient.
Data as of 27 Oct 2026, 23:13 UTC
- Patch
- Available – fixed in 1.16.2_2, 1.6.2
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 10 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade hatch to 1.16.2_2 or 1.6.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewhatchpkg:brew/hatchOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
## Impact TOCTOU (Time-of-Check-Time-of-Use) vulnerabilities in `virtualenv` allow local attackers to perform symlink-based attacks on directory creation operations. An attacker with local access can exploit a race condition between directory existence checks and creation to redirect virtualenv's app_data and lock file operations to attacker-controlled locations. **Affected versions:** All versions up to and including 20.36.1 **Affected users:** Any user running `virtualenv` on multi-user systems where untrusted local users have filesystem access to shared temporary directories or where `VIRTUALENV_OVERRIDE_APP_DATA` points to a user-writable location. **Attack scenarios:** - Cache poisoning: Attacker corrupts wheels or Python metadata in the cache - Information disclosure: Attacker reads sensitive cached data or metadata - Lock bypass: Attacker controls lock file semantics to cause concurrent access violations - Denial of service: Lock starvation preventing virtualenv operations ## Patches The vulnerability has been patched by replacing check-then-act patterns with atomic `os.makedirs(..., exist_ok=True)` operations. **Fixed in:** PR #3013 **Versions with the fix:** 20.36.2 and later Users should upgrade to version 20.36.2 or later. ## Workarounds If you cannot upgrade immediately: 1. Ensure `VIRTUALENV_OVERRIDE_APP_DATA` points to a directory owned by the current user with restricted permissions (mode 0700) 2. Avoid running `virtualenv` in shared temporary directories where other users have write access 3. Use separate user accounts for different projects to isolate app_data directories ## References - GitHub PR: https://github.com/pypa/virtualenv/pull/3013 - Vulnerability reported by: @tsigouris007 - CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization (TOCTOU) - CWE-59: Improper Link Resolution Before File Access
References
- github.com/pypa/virtualenv/security/advisories/GHSA-597g-3phw-6986 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-22702 (opens in a new tab)
- github.com/pypa/virtualenv/pull/3013 (opens in a new tab)
- github.com/pypa/virtualenv/commit/dec4cec5d16edaf83a00a658f32d1e032661cebc (opens in a new tab)
- github.com/pypa/virtualenv (opens in a new tab)