VulnerabilityPublished 30 Oct 2026

CVE-2026-110855: GitPython · separate_git_dir leaks env vars via crafted .gitmodules submodule name

Affects snakemakeSource GCVE Database

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Authoritative record:CVE-2026-110855· High 7.1

Not known to be exploited · CVSS 7.1 High : upgrade to 9.27.0_1 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 4.0 base score

7.1High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 9.27.0_1

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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: Passive
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: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
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 14 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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 snakemake to 9.27.0_1.

Affected software

Product	Affected	Fixed in
Homebrewsnakemake`pkg:brew/snakemake`Other threats	Affected >=5.5.3 <9.27.0_1	Fixed in 9.27.0_1

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 9.27.0_1. Users should upgrade to this version or later to prevent environment variable expansion in separate_git_dir derived from untrusted submodule names. Until upgraded, avoid cloning repositories with untrusted or suspicious .gitmodules content or disable debug-level logging to reduce exposure in logs.

Description

GitPython's _clone() method improperly expands environment variables in the separate_git_dir parameter derived from attacker-controlled .gitmodules submodule names. This leads to leakage of environment variable values as directory names on disk and in debug logs when cloning and updating submodules from a malicious repository. The flaw affects GitPython versions from 5.5.3 up to but not including 9.27.0_1 and has been fixed in 9.27.0_1.

Impact

An attacker controlling a repository's .gitmodules file can cause GitPython clients to leak environment variable values from the victim's environment. These secrets appear as directory names under .git/modules/ and in debug-level logs, potentially exposing sensitive credentials or secrets. This leakage persists on disk for the lifetime of the cloned repository. The vulnerability does not allow direct code execution or integrity compromise but leads to confidentiality loss of environment variables.

Summary

The vulnerability in GitPython arises because the _clone() method calls Git.polish_url() on the separate_git_dir argument without disabling environment variable expansion (expand_vars=False). Since separate_git_dir is constructed from the submodule name in .gitmodules, which is attacker-controlled, an attacker can embed environment variable syntax (e.g., $VAR) in the submodule name. When cloning and updating submodules, this causes os.path.expandvars() to expand the variable, leaking its value by creating directories named after the expanded secret and exposing it in debug-level Popen logs. This issue was not fixed by previous related advisories that added expand_vars=False in other call sites. The vulnerability is fixed in GitPython version 9.27.0_1.

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Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 06:14 UTC

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