CVE-2026-102925: Tox · virtualenv bash and fish activation scripts execute commands embedded in paths
Affects toxSource GCVE Database
Not known to be exploited · CVSS 7.8 High : upgrade to 4.62.0 soon.
Data as of 30 Oct 2026, 07:30 UTC
- Patch
- Available – fixed in 4.62.0
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 29 Sep 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 tox to 4.62.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewtoxpkg:brew/toxOther 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 The generated `activate` (bash/zsh) and `activate.fish` scripts interpolate a `shlex.quote`-ed value into a position that quotes it a second time. The extra quotes terminate the quoted run early and leave part of the value parsed as shell code, so a path containing shell metacharacters runs commands when a user sources the activation script. `activate` is affected through the virtual environment's own path, on the branch that reports a relocated environment: ```sh echo "Virtual environment directory __VIRTUAL_ENV__ does not exist!" >&2 ``` For a destination named `x'$(id)'y`, `shlex.quote` emits `'x'"'"'$(id)'"'"'y'`. The inner `"` closes the enclosing double quote and `$(id)` is left unquoted. Backtick and `;` payloads reach the same result. This branch runs whenever the recorded path is absent, which is the normal case for a virtual environment copied or distributed to another machine. `activate.fish` is affected through the interpreter's Tcl/Tk library paths: ```fish set -gx TCL_LIBRARY '__TCL_LIBRARY__' ``` `shlex.quote` already returns `'/tcl/(cmd)/lib'`, so the rendered line is `''/tcl/(cmd)/lib''`. fish concatenates the adjacent quoted runs and expands the `(cmd)` left between them. The same doubling also splits a path containing a space into two list elements, corrupting `TCL_LIBRARY` and `TK_LIBRARY`. This is the same defect class as GHSA-x78j-v8h9-3j2q, which covered `activate.bat`. ### Patches Fixed in 21.7.13 by moving the placeholders outside the surrounding quotes, so each value keeps only the quoting `shlex.quote` applied. Fix: https://github.com/pypa/virtualenv/pull/3252 ### Workarounds Avoid creating or distributing virtual environments whose path contains `'`, `` ` ``, `$`, `;`, `(` or `)`, and inspect the generated activation script before sourcing one you did not create.
References
- github.com/pypa/virtualenv/security/advisories/GHSA-p58f-9548-mpm2 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-102925 (opens in a new tab)
- github.com/pypa/virtualenv/pull/3252 (opens in a new tab)
- github.com/pypa/virtualenv/commit/4d5a105ec2a2723b8c7f4571bb68f4f71d01e3f6 (opens in a new tab)
- github.com/pypa/advisory-database/tree/main/vulns/virtualenv/PYSEC-2026-4013.yaml (opens in a new tab)
- github.com/pypa/virtualenv (opens in a new tab)
- github.com/pypa/virtualenv/releases/tag/21.7.13 (opens in a new tab)
- pypi.org/project/virtualenv (opens in a new tab)