Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
-
AccessHost crafted malicious web page
-
DeliveryVictim loads page in Firefox
-
ExploitAbuse DOM Navigation privilege flaw
-
ExecutionEscalate privileges within browser
-
ImpactCompromise confidentiality integrity availability
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V8 - Authorization Least privilege enforcement
MITRE ATT&CK
1 technique across 1 tactic: Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires a Firefox user (versions prior to 159) to load attacker-controlled web content that triggers the DOM: Navigation component flaw; per the CVSS vector no prior authentication or attacker privileges are needed (PR:N) but victim user interaction is required (UI:R), which is the primary limiting factor and prevents fully automated mass exploitation (SSVC Automatable: no). The specific configuration, markup, or navigation sequence that triggers the privilege-management defect is not described in the available sources. Exploitation is bounded to Firefox builds before 159; updating to Firefox 159 removes the flaw. |
| Impact | Signals are moderately consistent and point to a serious-but-not-emergency issue. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, base 8.8) describes a network-reachable, low-complexity flaw that needs no attacker privileges but does require user interaction - consistent with a browser vulnerability triggered when a victim visits attacker-controlled web content. SSVC tempers this: Exploitation is rated 'none' (no observed or public exploitation), Automatable 'no' (user interaction breaks fully automated mass exploitation), while Technical Impact is 'total', aligning with the C:H/I:H/A:H impact. There is no CISA KEV listing and no EPSS score was provided, so exploitation probability cannot be quantified from this data; the vuln.today Decision label is 'this_week', i.e. prioritized remediation but not act_now/emergency. No confirmed public exploit code is present - the vuldb and NVD/EUVD links are advisory references, not proof-of-concept exploits. Net: a genuinely high-severity, high-impact browser flaw worth patching promptly in the current cycle, but the required user interaction and absence of any exploitation evidence make it a prioritized routine fix rather than a drop-everything emergency. One caveat: the description labels this 'privilege escalation' and CWE-269 (improper privilege management), yet the vector carries UI:R and AV:N, so the realistic vector is a user visiting malicious web content rather than a local privilege-escalation primitive - the exact trigger is not described in the available sources. |
| Exploit ScenarioDerived | An attacker hosts or injects crafted web content that abuses the DOM Navigation component, then lures a Firefox user (via a link, ad, or compromised site) to load it. Because user interaction is required (UI:R), the victim must open the page; successful triggering escalates the attacker's privileges within the browser, yielding high confidentiality, integrity, and availability impact. No confirmed public exploit code is identified at time of analysis, and the precise trigger mechanism is not described in the available sources. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAIv1 – Oct 28, 2026
Privilege escalation in Mozilla Firefox's DOM: Navigation component allows remote attackers to gain elevated privileges within the browser when a victim loads attacker-controlled web content, with the flaw resolved in Firefox 159. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R, score 8.8) indicates no prior authentication or attacker privileges are needed, but the required victim interaction is the primary limiting factor and is consistent with CISA SSVC scoring of Automatable: no and Exploitation: none. No public exploit code or active exploitation has been identified at time of analysis, and the vendor-reported issue is tracked as Mozilla Bugzilla 2075440 with advisories mfsa2026-118 and mfsa2026-121.
RemediationAI
Upgrade to Firefox 159, which Mozilla identifies as the release in which this DOM: Navigation privilege escalation is fixed; the vendor advisories at https://www.mozilla.org/security/advisories/mfsa2026-118/ and https://www.mozilla.org/security/advisories/mfsa2026-121/ should be consulted for the precise build list per channel, since the advisories do not enumerate further fixed branches in the supplied data. Updating to Firefox 159 is described as removing the flaw entirely, and no separate configuration-based workaround is specified in the available sources; because exploitation requires the user to interact with attacker-controlled web content (UI:R) and CISA's SSVC assessment records Automatable: no, no emergency containment measure is indicated, and the issue is prioritized for this week's patching cycle. Verify the installed browser version after update and confirm the deployment matches the versions named in the Mozilla advisories before considering remediation complete.
Affected ProductsAI
Mozilla Firefox builds prior to version 159 are affected; Mozilla states the issue was fixed in Firefox 159, which is therefore the remediation boundary. No CPE strings were provided in the intelligence feed, so exact platform or channel-level CPE matching could not be performed. Coverage is documented across Mozilla security advisories MFSA2026-118 (https://www.mozilla.org/security/advisories/mfsa2026-118/) and MFSA2026-121 (https://www.mozilla.org/security/advisories/mfsa2026-121/), with the upstream engineering record in Bugzilla 2075440 (https://bugzilla.mozilla.org/show_bug.cgi?id=2075440) and secondary tracking under ENISA EUVD-2026-110906 and VulDB entry 427374.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
The vulnerability is classified as CWE-269 (Improper Privilege Management) and resides in the DOM: Navigation component of the Firefox browser engine, the subsystem responsible for handling navigation-related DOM operations on behalf of web content. Because the CVSS vector begins with AV:N and PR:N, the attack path is network-delivered and does not require the attacker to hold credentials or privileges in the target browser; UI:R reflects that the victim must interact with the malicious page for the privilege-management defect to be reached, and SSVC Automatable: no indicates CISA does not consider the flaw machine-exploitable at scale. The specific configuration, markup, or navigation sequence that triggers the defective privilege transition is not described in the available sources, so the precise root cause inside the Navigation component cannot be stated from the supplied data. Technical impact is rated total under SSVC, matching the C:H/I:H/A:H confidentiality, integrity and availability metrics, and the flaw is bounded to Firefox builds prior to 159 per the vendor advisories.
Know when Firefox gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Browser flaw reached over the network by loading malicious web content (AV:N, AC:L, PR:N) but needing the victim to visit the page (UI:R); SSVC 'total' impact supports C:H/I:H/A:H.
Primary rating from Vendor (mozilla).
CVSS VectorVendor: mozilla
Lifecycle Timeline
2DescriptionCVE.org
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 159.
Executive ViewAI
Mozilla Firefox contains a high-severity privilege escalation flaw (CVE-2026-118008) that could allow an attacker to gain elevated privileges within the browser when a user visits a malicious website. This affects all Firefox users on versions prior to 159, potentially exposing sensitive data or enabling further compromise. Leadership should prioritize patching due to the browser's widespread use and the potential for user data compromise.
Apply vendor patch.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.
Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderb
Use-after-free vulnerability in the serializeToStream implementation in the XMLSerializer component in Mozilla Firefox b
The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbi
The crypto.generateCRMFRequest function in Mozilla Firefox before 23.0, Firefox ESR 17.x before 17.0.8, Thunderbird befo
The XrayWrapper implementation in Mozilla Firefox before 35.0 and SeaMonkey before 2.32 does not properly interact with
The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.2, Thunderbi
The Web IDL implementation in Mozilla Firefox before 28.0, Firefox ESR 24.x before 24.4, Thunderbird before 24.4, and Se
Mozilla Firefox before 28.0, Firefox ESR 24.x before 24.4, Thunderbird before 24.4, and SeaMonkey before 2.25 allow remo
Integer underflow in the nsHtml5TreeBuilder class in the HTML5 string parser in Mozilla Firefox before 45.0 and Firefox
Mozilla Firefox before 37.0, Firefox ESR 31.x before 31.6, and Thunderbird before 31.6 do not properly restrict resource
Mozilla Firefox before 37.0 relies on docshell type information instead of page principal information for Window.webidl
The RC4 algorithm, as used in the TLS protocol and SSL protocol, has many single-byte biases, which makes it easier for
EUVD-2026-110906
GHSA-hm5r-6wjv-xfx3
NVD
CVE.org
EPSS
Vulnrichment
VulDB
Exploit-DB