nbdime · GitPython: Unsafe git option guard bypass via single-character kwarg value token smuggling enables arbitrary command
Affects nbdimeSource GCVE Database
Not known to be exploited · CVSS 8.7 High : upgrade to 4.0.4_5 soon.
Data as of 26 Oct 2026, 17:26 UTC
- EPSS
- 0.9% chance of exploitation in 30 days – higher than 60% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.0.4_5
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 13 Aug 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 nbdime to 4.0.4_5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewnbdimepkg:brew/nbdimeOther 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
A fix is available in GitPython version 4.0.4_5. Users should upgrade to this version or later to remediate the vulnerability. The fix involves enhancing the option guard to inspect tokens derived from both keys and values of kwargs or to check the fully transformed argv list rather than only the keys. Until upgrading, no other specific mitigations are indicated.
Description
GitPython versions up to 3.1.53 contain a vulnerability in the check_unsafe_options guard that allows bypass via single-character keyword argument value token smuggling. This enables arbitrary OS command execution through the --upload-pack git option in all guarded methods such as clone, fetch, pull, and others. The flaw arises because the guard inspects only the keys of kwargs for unsafe options, ignoring malicious tokens embedded in the values that become separate argv tokens. This vulnerability is fixed in version 4.0.4_5.
References
- github.com/gitpython-developers/GitPython/security/advisories/GHSA-r9mr-m37c-5fr3 (opens in a new tab)
- github.com/gitpython-developers/GitPython/pull/2180 (opens in a new tab)
- github.com/gitpython-developers/GitPython/commit/e8d0fbf774d1f6baa3b481adfe48bd262e43b453 (opens in a new tab)
- github.com/gitpython-developers/GitPython (opens in a new tab)
- github.com/gitpython-developers/GitPython/releases/tag/3.1.54 (opens in a new tab)