CVE Feed

    Dashboard / CVE / CVE-2026-8958

    CVE-2026-8958

    Information disclosure, sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

    Published:May 19, 2026
    Last Modified:May 20, 2026
    EPS:May 19, 2026
    EPSS Score:0.00042
    CVSS Score:8.6

    Affected Products

    Vendor
    Mozilla
    Product
    Firefox
    Vendor
    Mozilla
    Product
    Thunderbird

    Exploits

    No exploit reference

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs
    CAPEC-107 Cross Site Tracing
    CAPEC-127 Directory Indexing
    CAPEC-17 Using Malicious Files
    CAPEC-20 Encryption Brute Forcing
    CAPEC-22 Exploiting Trust in Client
    CAPEC-237 Escaping a Sandbox by Calling Code in Another Language
    CAPEC-36 Using Unpublished Interfaces or Functionality
    CAPEC-477 Signature Spoofing by Mixing Signed and Unsigned Content
    CAPEC-480 Escaping Virtualization
    CAPEC-51 Poison Web Service Registry
    CAPEC-57 Utilizing REST's Trust in the System Resource to Obtain Sensitive Data
    CAPEC-59 Session Credential Falsification through Prediction
    CAPEC-65 Sniff Application Code
    CAPEC-668 Key Negotiation of Bluetooth Attack (KNOB)
    CAPEC-74 Manipulating State
    CAPEC-87 Forceful Browsing

    Related CVEs

    CVE-2026-84144 (CVSS 7.5) — Internally found bugs present in Thunderbird 154 and Thunderbird ESR 153.1. Some of these bugs showed evidence…
    CVE-2026-84143 (CVSS 9.8) — Internally found bugs present in Thunderbird 154, Thunderbird ESR 153.1 and Thunderbird ESR 140.14. Some of th…
    CVE-2026-84142 (CVSS 9.8) — Internally found bugs present in Thunderbird 154. Some of these bugs showed evidence of memory corruption or a…
    CVE-2026-84141 (CVSS 9.8) — Integer overflow in the Graphics: ImageLib component. This vulnerability was fixed in Firefox 155, Firefox ESR…
    CVE-2026-84140 (CVSS 9.8) — Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ES…
    CVE-2026-84139 (CVSS 6.1) — Clickjacking issue in the DOM: Events component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.…
    CVE-2026-84138 (CVSS 6.5) — Denial-of-service in the PDF Viewer component. This vulnerability was fixed in Firefox 155 and Thunderbird 155…
    CVE-2026-84137 (CVSS 4.3) — Spoofing issue in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 155, Firefox ESR 153…
    CVE-2026-84136 (CVSS 6.1) — Other issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, …
    CVE-2026-84135 (CVSS 9.8) — Other issue in Firefox Focus for Android. This vulnerability was fixed in Firefox 155.…

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High