VulnTideExploited vulnerabilities, by vendor. Data as of 28 Oct 2026.
Known exploitedIn CISA's KEV catalog since 6 October 2025Ransomware use: unknown
Mozilla Multiple Products

CVE-2010-3765: Mozilla Multiple Products Remote Code Execution Vulnerability

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 6 Oct 2025, 5,458 days after the CVE record was published.

How likely is exploitation in the next 30 days?
83.2%

EPSS score, percentile 99.7 of all scored records

How severe?
9.8 Critical

CVSS v3.1 base score, from CISA's enrichment of the record

What should I do?

CISA deadline 27 Oct 2025. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Advisories and patches (12)

Which versions are affected?

Not stated. The CVE record gives vendor and product as “n/a” and the version as “unspecified”.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

What to do

Required action, set by CISA

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

CISA due date for this action: 27 October 2025.

Advisories and patches

Linked from CISA's catalog entry

Affected products and versions

The CVE record does not name affected products or versions: vendor and product are “n/a” and the version is “unspecified”.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

About this vulnerability

Mozilla Firefox, SeaMonkey, and Thunderbird contain an unspecified vulnerability when JavaScript is enabled. This allows remote attackers to execute arbitrary code via vectors related to nsCSSFrameConstructor::ContentAppended, the appendChild method, incorrect index tracking, and the creation of multiple frames, which triggers memory corruption.

Summary: CISA's KEV catalog, as of 28 Oct 2026.

  • CISA added CVE-2010-3765 to its Known Exploited Vulnerabilities (KEV) catalog on 6 Oct 2025.
  • CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
  • The due date CISA sets for the required action is 27 Oct 2025.
  • The CVE record was published on 27 Oct 2010, 5,458 days before it was added to KEV.
  • The CVE record carries a CVSS v3.1 base score of 9.8 (Critical), taken from CISA's enrichment of the record.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 83.2% (percentile 99.7), as of 28 Oct 2026.
  • CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.

Description

Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before 3.1.6 and 3.0.x before 3.0.10, and SeaMonkey 2.x before 2.0.10, when JavaScript is enabled, allows remote attackers to execute arbitrary code via vectors related to nsCSSFrameConstructor::ContentAppended, the appendChild method, incorrect index tracking, and the creation of multiple frames, which triggers memory corruption, as exploited in the wild in October 2010 by the Belmoo malware.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

Weakness

  • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.

Timeline

DateEvent
27 Oct 2010CVE record published
6 Oct 2025Added to CISA KEV
22 Oct 2025CVE record last updated
27 Oct 2025CISA due date for the required action

References

    39 more in the CVE record.

    More exploited Mozilla vulnerabilities

    • CVE-2024-9680: Mozilla Firefox Use-After-Free Vulnerability (added 15 Oct 2024)
    • CVE-2016-9079: Mozilla Firefox, Firefox ESR, and Thunderbird Use-After-Free Vulnerability (added 22 Jun 2023)
    • CVE-2015-4495: Mozilla Firefox Security Feature Bypass Vulnerability (added 25 May 2022)
    • CVE-2019-11707: Mozilla Firefox and Thunderbird Type Confusion Vulnerability (added 23 May 2022)
    • CVE-2019-11708: Mozilla Firefox and Thunderbird Sandbox Escape Vulnerability (added 23 May 2022)
    • CVE-2013-1690: Mozilla Firefox and Thunderbird Denial-of-Service Vulnerability (added 28 Mar 2022)