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VulnerabilityPublished

CVE-2026-113718: virtualenv · Xonsh activation literals depend on the script decoding codec

Affects virtualenvwrapperSource GCVE Database

0
Authoritative record:CVE-2026-113718· High 7.1

Not known to be exploited · CVSS 7.1 High : upgrade to 6.1.1_4 soon.

Data as of 27 Oct 2026, 06:43 UTC

CVSS 4.0 base score
7.1High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 6.1.1_4
CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 20 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 virtualenvwrapper to 6.1.1_4.

Affected software

ProductAffectedFixed in
Homebrewvirtualenvwrapperpkg:brew/virtualenvwrapperOther threatsAffected
  • >=6.1.1_3 <6.1.1_4
Fixed in
  • 6.1.1_4

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available in virtualenv version 6.1.1_4 that changes the quoting method to escape non-ASCII characters, preventing the decoding issue. Users should upgrade to version 6.1.1_4 or later and regenerate any existing activate.xsh files to ensure the fix is applied. No other mitigation is required if the patched version is used.

Description

A vulnerability in virtualenv's xonsh activation script allows attacker-controlled prompt text to become executable code during environment activation if the xonsh source decoding uses legacy multibyte encodings like GBK or Big5. This occurs because UTF-8 encoded activation scripts containing non-ASCII characters are misinterpreted under these encodings, causing string literals to be improperly closed and arbitrary statements to execute. The issue affects POSIX activation scripts and requires an attacker to control the prompt or destination argument passed to virtualenv and a user to source the generated activation script. A fix is available in virtualenv version 6.1.1_4.

References

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