Security readout for executives and security teams
Plain-English summary
Firefox contained an integer-overflow flaw in a JavaScript engine data structure. The supplied CVSS score is 9.8, indicating potentially severe confidentiality, integrity, and availability consequences. Mozilla fixed the issue in Firefox 139.0.4, but the sources do not specify the complete affected-version range.
Executive priority
Treat remediation as urgent because the vendor assigns a critical 9.8 score and the vulnerable component processes JavaScript. Accelerate browser updates and verify coverage, while avoiding unsupported claims that exploitation is occurring.
Technical view
CVE-2025-49710 is a CWE-190 integer overflow in the JavaScript engine's OrderedHashTable. Its CVSS 3.1 vector reports network reachability, low complexity, no privileges, and no user interaction. The available evidence does not describe the resulting memory corruption, execution primitive, or exact vulnerable-version boundary.
Likely exposure
Prioritize Firefox installations that have not received the 139.0.4 fix. The supplied sources do not identify the earliest affected version, specific release channels, or whether every earlier Firefox release is vulnerable.
Exploitation context
The CVE is not listed as KEV in the supplied bundle, and no cited evidence establishes active exploitation or a public exploit. This absence does not prove exploitation is impossible; it limits what can be claimed.
Researcher notes
The evidence identifies the vulnerable structure and overflow class but provides no trigger conditions, root-cause detail, vulnerable-version floor, proof of concept, or confirmed exploitation. Further assessment should remain defensive and follow Mozilla's advisory and Bugzilla record.
Mitigation direction
- Upgrade Firefox to 139.0.4 or a currently supported newer release.
- Prioritize internet-facing, privileged, and high-value user endpoints.
- Review Mozilla's advisory for channel-specific or enterprise deployment guidance.
- Temporarily restrict outdated Firefox installations until updates are verified.
Validation and detection
- Inventory Firefox versions across managed and unmanaged endpoints.
- Confirm each installation reports version 139.0.4 or newer.
- Verify update deployment success through endpoint-management telemetry.
- Re-scan endpoints for outdated Firefox installations after remediation.
- Monitor Mozilla guidance for revised affected-version or exploitation information.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-190: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2025-49710 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.mozilla.org/show_bug.cgi?id=1970095CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2025-47/CVE reference, mozilla
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Integer Overflow or Wraparound
Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.