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 bef
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.
- Published
- Oct 27, 2010
- Updated
- Jun 16, 2026
- EPSS
- 83.2% · 100th percentile
- CWE
- CWE-119
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Report tools
Action score
94
Now
Patch today or shut off access.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 30 / 30 · Listed
- EPSS
- 25 / 30 · 83.2%
CISA SSVC decision
- Exploitation
- active
- Automatable
- yes
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
Actively exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on Oct 6, 2025. That signals real attacks, not theory.
Remediation deadline for government agencies: Oct 27, 2025.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| mozilla | firefox | cpe:2.3:a:mozilla:firefox |
| mozilla | thunderbird | cpe:2.3:a:mozilla:thunderbird |
| mozilla | seamonkey | cpe:2.3:a:mozilla:seamonkey |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- mozilla firefox3.5
- mozilla firefox3.5.1
- mozilla firefox3.5.10
- mozilla firefox3.5.11
- mozilla firefox3.5.12
- mozilla firefox3.5.13
- mozilla firefox3.5.14
- mozilla firefox3.5.2
- mozilla firefox3.5.3
- mozilla firefox3.5.4
- mozilla firefox3.5.5
- mozilla firefox3.5.6
- mozilla firefox3.5.7
- mozilla firefox3.5.8
- mozilla firefox3.5.9
- mozilla firefox3.6
- mozilla firefox3.6.10
- mozilla firefox3.6.11
- mozilla firefox3.6.2
- mozilla firefox3.6.3
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:5.0 | xulrunner | before 1.9.0.19-6 | 1.9.0.19-6 |
| Red Hat:enterprise_linux:3::as | seamonkey | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-chat | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-debuginfo | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-devel | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-dom-inspector | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-js-debugger | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-mail | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-nspr | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-nspr-devel | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-nss | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:3::as | seamonkey-nss-devel | before 0:1.0.9-0.62.el3 | 0:1.0.9-0.62.el3 |
| Red Hat:enterprise_linux:4::as | firefox | before 0:3.6.11-4.el4_8 | 0:3.6.11-4.el4_8 |
| Red Hat:enterprise_linux:4::as | firefox-debuginfo | before 0:3.6.11-4.el4_8 | 0:3.6.11-4.el4_8 |
| Red Hat:enterprise_linux:4::as | seamonkey | before 0:1.0.9-65.el4_8 | 0:1.0.9-65.el4_8 |
| Red Hat:enterprise_linux:4::as | seamonkey-chat | before 0:1.0.9-65.el4_8 | 0:1.0.9-65.el4_8 |
| Red Hat:enterprise_linux:4::as | seamonkey-debuginfo | before 0:1.0.9-65.el4_8 | 0:1.0.9-65.el4_8 |
| Red Hat:enterprise_linux:4::as | seamonkey-devel | before 0:1.0.9-65.el4_8 | 0:1.0.9-65.el4_8 |
| Red Hat:enterprise_linux:4::as | seamonkey-dom-inspector | before 0:1.0.9-65.el4_8 | 0:1.0.9-65.el4_8 |
| Red Hat:enterprise_linux:4::as | seamonkey-js-debugger | before 0:1.0.9-65.el4_8 | 0:1.0.9-65.el4_8 |
| Red Hat:enterprise_linux:4::as | seamonkey-mail | before 0:1.0.9-65.el4_8 | 0:1.0.9-65.el4_8 |
| Red Hat:enterprise_linux:4::as | thunderbird | before 0:1.5.0.12-33.el4 | 0:1.5.0.12-33.el4 |
| Red Hat:enterprise_linux:4::as | thunderbird-debuginfo | before 0:1.5.0.12-33.el4 | 0:1.5.0.12-33.el4 |
| Red Hat:enterprise_linux:5::client | thunderbird | before 0:2.0.0.24-10.el5_5 | 0:2.0.0.24-10.el5_5 |
+11
Same product
mozilla: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-11708Insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes can result in the non-sandboxeKEV87Now
- CVE-2015-4495The PDF reader in Mozilla Firefox before 39.0.3, Firefox ESR 38.x before 38.1.1, and Firefox OS before 2.2 allows remote attackers to bypassKEV86Now
- CVE-2013-1690Mozilla Firefox before 22.0, Firefox ESR 17.x before 17.0.7, Thunderbird before 17.0.7, and Thunderbird ESR 17.x before 17.0.7 do not properKEV86Now
- CVE-2019-17026Incorrect alias information in IonMonkey JIT compiler for setting array elements could lead to a type confusion.KEV79This week
- CVE-2024-9680An attacker was able to achieve code execution in the content process by exploiting a use-after-free in Animation timelines.KEV76This week
- CVE-2019-11707A type confusion vulnerability can occur when manipulating JavaScript objects due to issues in Array.pop.KEV76This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:xulrunner | 1.9.0.19-6 · Debian:5.0 | Package registry (OSV) |
| red hat:firefox | 0:3.6.11-4.el4_8 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:firefox-debuginfo | 0:3.6.11-4.el4_8 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:seamonkey | 0:1.0.9-0.62.el3 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:seamonkey-chat | 0:1.0.9-0.62.el3 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:seamonkey-debuginfo | 0:1.0.9-0.62.el3 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:seamonkey-devel | 0:1.0.9-0.62.el3 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:seamonkey-dom-inspector | 0:1.0.9-0.62.el3 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:seamonkey-js-debugger | 0:1.0.9-0.62.el3 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:seamonkey-mail | 0:1.0.9-0.62.el3 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:xulrunner | 0:1.9.2.11-4.el5_5 · Red Hat:enterprise_linux:5::client_workstation | Package registry (OSV) |
| red hat:xulrunner-debuginfo | 0:1.9.2.11-4.el5_5 · Red Hat:enterprise_linux:5::client_workstation | Package registry (OSV) |
| red hat:xulrunner-devel | 0:1.9.2.11-4.el5_5 · Red Hat:enterprise_linux:5::client_workstation | Package registry (OSV) |
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×1
- Exploit-DB entry ×4
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | dos | 2010-10-28 |
| Exploit-DB entry | dos | 2010-10-28 |
| Exploit-DB entry | remote | 2011-02-22 |
| Exploit-DB entry | remote | 2010-10-29 |
| Metasploit module | exploit/windows/browser/mozilla_interleaved_writeMozilla Firefox Interleaved document.write/appendChild Memory Corruptionexploit | 2010-10-25 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Metasploit-3 d
- Published
- First PoCsame day
- CISA KEV+5457 d
- TodaySep 30, 2026+5817 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Buffer ManipulationCAPEC-123likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- secunia.com/advisories/41969
- blog.mozilla.com/security/2010/10/26/critical-vulnerability-in-firefox-3-5-and-firefox-3-6/
- blogs.sun.com/security/entry/multiple_vulnerabilities_in_mozilla_firefox
- isc.sans.edu/diary.html?storyid=9817
- lists.fedoraproject.org/pipermail/package-announce/2010-November/050233.html
- lists.fedoraproject.org/pipermail/package-announce/2010-October/050061.html
- lists.fedoraproject.org/pipermail/package-announce/2010-October/050077.html
- lists.fedoraproject.org/pipermail/package-announce/2010-October/050154.html
- norman.com/about_norman/press_center/news_archive/2010/129223/en?utm_source=twitterfeed&utm_medium=twitter
- secunia.com/advisories/41761
- secunia.com/advisories/41965
- secunia.com/advisories/41966
- secunia.com/advisories/41975
- secunia.com/advisories/42003
- secunia.com/advisories/42008
- secunia.com/advisories/42043
- secunia.com/advisories/42867
- slackware.com/security/viewer.php?l=slackware-security&y=2010&m=slackware-security.556706
- support.avaya.com/css/P8/documents/100114329
- support.avaya.com/css/P8/documents/100114335
Vendor advisories and official records. Exploit/PoC links are deliberately left out.