VulnerabilityPublished 1 Oct 2026Updated 26 Oct 2026

CVE-2026-100689: Cf2tf · GitPython submodule update path traversal can write outside the repository

Affects cf2tfSource GCVE Database

Authoritative record:CVE-2026-100689· High 8.7

Not known to be exploited · CVSS 8.7 High : upgrade to 0.9.2_10 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: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.9.2_10

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 26 Sep 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_10.

Affected software

Product	Affected	Fixed in
Homebrewcf2tf`pkg:brew/cf2tf`Other threats	Affected >=0.6.1 <0.9.2_10	Fixed in 0.9.2_10

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

Description

**Affected:** `GitPython` **3.1.61** (latest release) and `main` — `git/objects/submodule/base.py`. `git diff 3.1.61 origin/main -- git/objects/submodule/` is empty, so both are identical here. --- ## The gap The fix for `GHSA-hmq2-w58f-27jc` added `Submodule._validated_name()` and wired it into `update()` and five siblings, closing the `.gitmodules` **name** → `.git/modules/<name>` traversal. The other attacker-controlled `.gitmodules` field, **`path`**, is read raw: ```python # git/objects/submodule/base.py:172-177 def _set_cache_(self, attr): if attr in ("path", "_url", "_branch_path"): reader = self.config_reader() self.path = reader.get("path") # raw .gitmodules value ``` and GitPython's own containment guard is applied in only two of the places that consume it: ``` 400: def _to_relative_path(cls, parent_repo, path) # the guard (abspath + commonpath containment) 542: path = cls._to_relative_path(repo, path) # add() — guarded 1041: module_checkout_path = self._to_relative_path(self.repo, module_path) # move() — guarded ``` `update()` validates only the name and then uses the path-derived absolute location directly: ``` 788: self._validated_name(self.name) # NAME only 801: checkout_module_abspath = self.abspath # derived from self.path — unguarded 821: os.makedirs(checkout_module_abspath, exist_ok=True) ``` So `path = ../../../tmp/escaped` in an attacker-authored `.gitmodules` selects the directory that gets created and, on the clone path, populated from the submodule URL. The same absolute location is what `force_remove` hands to `shutil.rmtree`. The asymmetry is the argument: this is not a missing concept — the project wrote `_to_relative_path()` precisely for this, and `add()`/`move()` use it. `update()` does not. ## Honest limits (please read before rating) - **The most common flow is not affected.** `Repo.clone_from(...)` → `repo.submodules` → `sm.update(init=True)` re-derives `path` from a canonical tree lookup, and real git refuses to check out a tree containing a `..` component, so an evil `.gitmodules` never lands in the working tree in the first place. A reachable trigger therefore requires the victim's code to name a **non-HEAD commit** (a historical-commit API such as `submodule_update(previous_commit=...)`). - **The researcher did not build that end-to-end trigger.** The researcher only verified first-hand the code above: the guard's two call sites, the name-only validation in `update()`, and the unguarded `abspath` → `os.makedirs()` flow at 3.1.61 == `main`. ## Suggested fix Apply the guard the project already has, wherever the path is consumed: ```python # in update(), before deriving abspath (and in any other consumer of self.path): checkout_rel = self._to_relative_path(self.repo, self.path) # raises if it escapes the working tree ``` Better still, validate at the boundary: reject a `.gitmodules` entry whose `path` is absolute or contains a `..` component when the section is first read in `_set_cache_()`/`iter_items()`, so no consumer can be added later without the check. A regression test with `path = ../escaped` alongside the existing `name` test would pin both fields. ## Prior art checked `GHSA-hmq2-w58f-27jc` (this is a residual of its fix, in the sibling field, not a re-report) plus the repository's 30 published advisories — none mentions the `path` field or `_to_relative_path`. Searched issues and PRs for `_to_relative_path`, `gitmodules path` and `submodule traversal`: no report of this. ## Credit **kta1kri**. --- ## Appendix — `EVIDENCE_gitpython_path_unguarded_20260901.txt` (inlined; advisories accept no attachments) ```text === EVIDENCE: GitPython — the .gitmodules 'path' field reaches os.makedirs()/clone unguarded === Mon Aug 31 18:45:22 UTC 2026 --- artifact: tag 3.1.61 (latest release); git diff 3.1.61 origin/main -- git/objects/submodule/ is empty --- --- the containment guard GitPython owns, and its only two call sites --- 33: _to_relative_path, 400: def _to_relative_path(cls, parent_repo: "Repo", path: PathLike) -> PathLike: 407: path = _to_relative_path(parent_repo.working_tree_dir, path) 542: path = cls._to_relative_path(repo, path) 1041: module_checkout_path = self._to_relative_path(self.repo, module_path) --- the parent fix (_validated_name) call sites: it validates the NAME --- 309: def _validated_name(cls, name: str) -> str: 321: name = cls._validated_name(name) 541: cls._validated_name(name) 788: self._validated_name(self.name) 1040: self._validated_name(self.name) 1181: self._validated_name(self.name) 1439: self._validated_name(self.name) 1440: self._validated_name(new_name) 1489: self._validated_name(self.name) --- update(): name validated, path not; abspath -> os.makedirs --- try: self._validated_name(self.name) # ENSURE RE

References

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