CVE-2026-110859VulnerabilityPublished 30 Oct 2026

tern · GitPython: arbitrary file read via attacker-controlled branch name in `Head.checkout()` (incomplete fix of

Affects ternSource GCVE Database

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Authoritative record:CVE-2026-110859· High 8.7

Not known to be exploited · CVSS 8.7 High.

Data as of 30 Oct 2026, 06:59 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 32% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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 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

Affected software

Product	Affected	Fixed in
Homebrewtern`pkg:brew/tern`Other threats	Affected >=2.12.0	Fixed in–

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AI-suggested

Users should upgrade GitPython to a version later than 3.1.62 once an official fix is released. Until patched, avoid cloning untrusted repositories or performing checkout operations on branches controlled by untrusted sources. Monitor the vendor advisory for updates. The vulnerability is due to incomplete sanitization of positional arguments in Head.checkout(), so patching will require applying the same positional argument checks as done for other similar methods.

Description

GitPython versions up to 3.1.62 contain a vulnerability in the Head.checkout() method where an attacker-controlled branch name can be used to perform an arbitrary file read. This occurs because the branch name is passed as a positional argument to git checkout without proper sanitization or argument separation, allowing injection of git options like --pathspec-from-file. The flaw was incompletely fixed in prior advisories, leaving Head.checkout vulnerable. An attacker who can cause the application to clone a repository they control can exploit this to read any file accessible by the application process, with no authentication or privileges required.

Impact

An unauthenticated attacker who can cause the application to clone a repository they control can read any file that the application process has access to. This includes sensitive system files such as /etc/passwd. The attack requires no credentials or privileges in the consuming application. The vulnerability can lead to exposure of sensitive information, potentially aiding further attacks or reconnaissance. The real-world likelihood is high because cloning user-supplied URLs is a common use case for GitPython in CI systems, importers, scanners, and bots.

Summary

The vulnerability in GitPython (<= 3.1.62) arises from Head.checkout() not properly sanitizing its positional argument (the branch name) before passing it to the underlying git checkout command. Unlike keyword arguments, which are guarded against unsafe git options, the positional branch name can include malicious options such as --pathspec-from-file=/etc/passwd. When the application clones a repository with a default branch named with such a payload, the checkout command leaks the contents of arbitrary files via exceptions. This issue is a partial regression of fixes applied to similar vulnerabilities (CVE-2026-76217 and CVE-2026-78679) where positional argument checks were not applied to Head.checkout. The vulnerability has a CVSS 3.1 score of 7.5 (High) and affects all published releases up to 3.1.62, including the main branch at commit 4905b4af.

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What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 05:53 UTC

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