Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-2802 is a medium-severity Race Condition (CWE-362) vulnerability in Mozilla Firefox. Its CVSS base score is 4.2 (Medium).
Operationally, ranked at the 10th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-39 (Process Isolation) and SC-4 (Information in Shared System Resources) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-2802 is a race condition vulnerability (CWE-362) in the JavaScript Garbage Collector (GC) component of Mozilla Firefox and Thunderbird. It affects versions prior to Firefox 148 and Thunderbird 148, where the flaw allows concurrent access issues during garbage collection operations in JavaScript execution. The vulnerability has a CVSS v3.1 base score of 4.2 (AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N), rated as Medium severity due to its network accessibility but high attack complexity and requirement for user interaction.
An unauthenticated remote attacker can exploit this vulnerability by crafting malicious web content that triggers the race condition in the JavaScript GC, typically requiring the user to interact with a malicious webpage or link. Successful exploitation could result in limited impacts, such as low-level disclosure of sensitive information or minor modification of data, without affecting availability or escalating privileges.
Mozilla's security advisories (MFSA 2026-13 and MFSA 2026-16) and the associated Bugzilla entry (bug 2011069) confirm the issue was addressed in Firefox 148 and Thunderbird 148. Security practitioners should prioritize updating affected browsers to these patched versions to mitigate the risk, as no workarounds are detailed in the provided references.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8454
Vulnerability Data
Race condition in the JavaScript: GC component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Maintaining separate execution domains for each process structurally eliminates unintended concurrent access to the same shared resources.
Preventing unintended information transfer through shared system resources directly addresses the improper concurrent modification that defines a race condition.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
A.8.25 mandates secure SDLC practices (secure coding guidelines, security requirements, checkpoints, testing including code scans/penetration tests, developer training) that reach race conditions in concurrent code, but only as one slice of a broad requirement whose implementation scope and rigour are left to the organisation.
A.8.26 explicitly lists resilience against malicious attacks including SQL injections and input validation as application security requirements to identify/address; race conditions are a similar class of timing-based concurrency flaw that can be mitigated by requirements for proper synchronization/locking, but this is only one slice of the broad CWE-362 class (most instances arise in low-level shared-memory or TOCTOU scenarios not named here).
Secure architecture principles require proper synchronization and resource isolation, addressing the root cause of CWE-362.
Secure coding standards explicitly forbid unsafe concurrent access patterns and mandate atomic operations or locks.
Security testing can detect race conditions, but does not prevent them at design or coding time.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-362, a class-level weakness, and none of its children carries one either.