CVE-2025-11940VulnerabilityPublished 19 Oct 2025Updated 20 Oct 2025

CVE-2025-11940: LibreWolf · Uncontrolled Search Path

Affects LibreWolfSource CVE Database V5

Not known to be exploited · CVSS 7.3 High · fixed in 144.0 : patch LibreWolf soon.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 4.0 base score

7.3High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 144.0

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

Attack Vector: Local
Attack Complexity: High
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: High
Vulnerable system availability: High
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: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity: High: The successful attack depends on the evasion or circumvention of security-enhancing techniques in place that would otherwise hinder the attack. These include: Evasion of exploit mitigation techniques, for example, circumvention of address space randomization (ASLR) or data execution prevention (DEP) must be performed for the attack to be successful; Obtaining target-specific secrets. The attacker must gather some target-specific secret before the attack can be successful. A secret is any piece of information that cannot be obtained through any amount of reconnaissance. To obtain the secret the attacker must perform additional attacks or break otherwise secure measures (e.g. knowledge of a secret key may be needed to break a crypto channel). This operation must be performed for each attacked target.
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: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
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: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
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 19 Oct 2025
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 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
GitHublibrewolf/librewolf`pkg:github/librewolf/librewolf`Other threats	Affected =143.0.4-1	Fixed in–

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AI-suggested

European organizations should immediately upgrade all affected LibreWolf installations on Windows to version 144.0-1 or later, which contains the patch addressing this vulnerability. Additionally, organizations should enforce strict local access controls and monitor for unauthorized local activity, especially on systems where LibreWolf is installed. Implement application whitelisting to prevent execution of unauthorized installers or scripts. Regularly audit and restrict user privileges to minimize the risk of local exploitation. Employ endpoint detection and response (EDR) solutions to detect suspicious installer behavior or attempts to manipulate file paths. Finally, educate users and administrators about the risks of local attacks and the importance of applying security updates promptly.

Description

A security vulnerability has been detected in LibreWolf up to 143.0.4-1 on Windows. This affects an unknown function of the file assets/setup.nsi of the component Installer. Such manipulation leads to uncontrolled search path. The attack must be carried out locally. Attacks of this nature are highly complex. The exploitability is reported as difficult. Upgrading to version 144.0-1 mitigates this issue. The name of the patch is dd10e31dd873e9cb309fad8aed921d45bf905a55. It is suggested to upgrade the affected component.

Impact

For European organizations, this vulnerability could allow a local attacker to execute arbitrary code during the installation or update of LibreWolf on Windows systems, potentially leading to unauthorized access, data compromise, or system integrity violations. This is particularly concerning for organizations that rely on LibreWolf for secure browsing or have strict security policies requiring trusted software installation. The ability to manipulate the installer’s search path could facilitate privilege escalation or persistence mechanisms. Although exploitation is complex and requires local access, insider threats or attackers who gain initial footholds could leverage this vulnerability to deepen their control. The impact extends to confidentiality, integrity, and availability of affected systems, potentially disrupting business operations or exposing sensitive data.

Summary

CVE-2025-11940 identifies a security vulnerability in the LibreWolf browser's Windows installer component, specifically within the assets/setup.nsi script used during installation. The vulnerability arises from an uncontrolled search path, meaning the installer may load files or dependencies from unintended or attacker-controlled locations. This can lead to the execution of malicious code with the privileges of the installer process. The attack requires local access with limited privileges and does not require user interaction, but the complexity of the attack is high, making exploitation difficult. The vulnerability impacts LibreWolf versions up to 143.0.4-1 on Windows platforms. The issue is resolved in version 144.0-1 by applying a patch identified by commit dd10e31dd873e9cb309fad8aed921d45bf905a55. The CVSS 4.0 vector (AV:L/AC:H/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X) indicates local attack vector, high attack complexity, low privileges required, no user interaction, and high impact on confidentiality, integrity, and availability. No known exploits have been reported in the wild, but the vulnerability poses a significant risk if leveraged by a local attacker to compromise system security during installation or update processes.

References

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