VulnerabilityPublished 1 Oct 2026Updated 26 Oct 2026

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

Affects nbdimeSource GCVE Database

Authoritative record:CVE-2026-100689· High 8.7

Not known to be exploited · CVSS 8.7 High : upgrade to 4.0.4_9 soon.

Data as of 26 Oct 2026, 17:42 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 4.0.4_9

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 nbdime to 4.0.4_9.

Affected software

Product	Affected	Fixed in
Homebrewnbdime`pkg:brew/nbdime`Other threats	Affected >=1.1.0 <4.0.4_9	Fixed in 4.0.4_9

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 GitPython version 4.0.4_9 that applies the containment guard to the 'path' field during submodule updates, preventing directory traversal. Users should upgrade to version 4.0.4_9 or later to remediate this vulnerability. The vendor advisory confirms the fix is present in this release. No additional mitigation is required if the patched version is used. For unpatched versions, avoid using submodule update operations on non-HEAD commits or untrusted .gitmodules files.

Description

CVE-2026-100689 is a path traversal vulnerability in GitPython 3.1.61 and main branch affecting the handling of the .gitmodules 'path' field during submodule updates. The vulnerability arises because the 'path' field is used without proper containment checks, allowing an attacker to specify a path outside the repository directory. This can lead to directory creation and file writes outside the intended repository location. The issue is mitigated in common workflows since Git prevents checkout of trees with '..' components, but it can be triggered when updating submodules at non-HEAD commits via the API. A fix is available in GitPython version 4.0.4_9 that applies the existing containment guard to the 'path' field.

Impact

An attacker who can supply a malicious .gitmodules file with a crafted 'path' field can cause GitPython's submodule update process to write files outside the repository directory. This can lead to arbitrary directory creation and potential overwriting of files outside the intended scope, which may be leveraged for code execution or system compromise depending on the context. However, exploitation requires a non-standard usage pattern such as updating submodules at non-HEAD commits via the API, limiting the attack surface. The vulnerability has a CVSS 4.0 score of 6.1 (medium severity) reflecting network attack vector, high attack complexity, and partial impact on confidentiality and integrity.

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Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 17:42 UTC

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