CVE-2025-14321VulnerabilityPublished 5 Jan 2026Updated 13 Oct 2026

Red Hat Security Advisory: firefox security update

Affects Red Hat firefoxSource GCVE Database

Mentioned vulnerabilities

Authoritative record:CVE-2025-14321· Critical 9.8

Not known to be exploited · CVSS 9.8 Critical.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

9.8Critical

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Dec 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

AI-suggested

Red Hat has released updated Firefox and Thunderbird packages for Red Hat Enterprise Linux 8.8 that address these vulnerabilities. Users should apply these official updates promptly to remediate the issues. For detailed update instructions, refer to Red Hat's advisory and article at https://access.redhat.com/articles/11258. No additional mitigation steps are indicated beyond applying the vendor-provided patches.

Description

Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in Red Hat Enterprise Linux 8.8 updates. These include memory safety bugs, use-after-free, JIT miscompilation, sandbox escape, privilege escalation, and same-origin policy bypass issues in various components such as WebRTC signaling, JavaScript engine, graphics CanvasWebGL, Netmonitor, request handling, and DOM notifications. Red Hat has released updated packages for Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146, and Thunderbird 146 to remediate these issues.

Impact

The vulnerabilities collectively could allow attackers to exploit memory safety bugs, execute use-after-free attacks, cause incorrect just-in-time (JIT) compilation, escape sandbox restrictions, escalate privileges within the browser context, and bypass same-origin policy protections. These issues affect core browser components that handle web content rendering, scripting, networking, and notifications, potentially compromising browser security and user data integrity if exploited. No known exploits in the wild have been reported at this time.

CWE-94Improper Control of Generation of Code ('Code Injection') (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #10OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
Architecture and Design · Refactoring
Refactor your program so that you do not have to dynamically generate code.
Architecture and Design
Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V5.2.8 (opens in a new tab)
V5.2.5 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
Leverage Executable Code in Non-Executable Files (opens in a new tab)
Manipulating User-Controlled Variables (opens in a new tab)
Code Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 13 Oct 2026, 22:08 UTC

WeaknessesCWE-94

Technical details

References

Community reviews

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