Full Report
Mozilla security advisory (AV26-868)
Analysis Summary
# Vulnerability: Multiple Vulnerabilities in Mozilla Firefox and Firefox ESR
## CVE Details
- **CVE ID:** Multiple (Refer to MFSA2026-82 through MFSA2026-85)
- **CVSS Score:** 9.8 (Critical) - *Estimated based on historical Mozilla Foundation Security Advisory severity for "Critical" impact.*
- **CWE:** Varies (Typically includes Memory Safety, Use-After-Free, and Type Confusion)
## Affected Systems
- **Products:** Firefox and Firefox ESR (Extended Support Release)
- **Versions:**
- Firefox ESR versions prior to 115.40
- Firefox ESR versions prior to 140.15
- Firefox ESR versions prior to 153.2
- Firefox (Standard) versions prior to 155
- **Configurations:** Default installations are affected.
## Vulnerability Description
While the advisory (AV26-868) acts as a high-level notification, these specific Mozilla Foundation Security Advisories (MFSA) typically address memory safety bugs, buffer overflows, and logic flaws. These vulnerabilities could allow an attacker to bypass security restrictions, execute arbitrary code, or cause a denial of service (browser crash) by enticing a user to view a specially crafted web page.
## Exploitation
- **Status:** Not explicitly stated as "exploited in the wild" in this bulletin, but generally treated as high-risk upon disclosure.
- **Complexity:** Low to Medium
- **Attack Vector:** Network (Remote/Web-based)
## Impact
- **Confidentiality:** High (Potential for data theft and session hijacking)
- **Integrity:** High (Potential for arbitrary code execution)
- **Availability:** High (Potential for application crashes and instability)
## Remediation
### Patches
Mozilla has released the following versions to address these flaws:
- **Firefox ESR 115.40**
- **Firefox ESR 140.15**
- **Firefox ESR 153.2**
- **Firefox 155**
### Workarounds
- No specific workarounds are provided; users are strongly advised to update to the latest patched version immediately.
- As a general security practice, avoid visiting untrusted websites or clicking on suspicious links.
## Detection
- **Indicators of compromise:** Unusual browser crashes, unexpected outgoing network traffic to unknown IPs, or unauthorized modifications to browser settings.
- **Detection methods and tools:** Enterprise vulnerability scanners should be updated to check for outdated versions of the `firefox.exe` binary.
## References
- Mozilla Foundation Security Advisories: hxxps[://]www[.]mozilla[.]org/en-US/security/advisories/
- MFSA2026-82: hxxps[://]www[.]mozilla[.]org/en-US/security/advisories/mfsa2026-82/
- MFSA2026-83: hxxps[://]www[.]mozilla[.]org/en-US/security/advisories/mfsa2026-83/
- MFSA2026-84: hxxps[://]www[.]mozilla[.]org/en-US/security/advisories/mfsa2026-84/
- MFSA2026-85: hxxps[://]www[.]mozilla[.]org/en-US/security/advisories/mfsa2026-85/
- Canadian Centre for Cyber Security: hxxps[://]www[.]cyber[.]gc[.]ca/en/alerts-advisories/mozilla-security-advisory-av26-868