Invalid pointer in the JavaScript: WebAssembly component
Invalid pointer in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.
- Published
- Sep 29, 2026
- Updated
- Oct 1, 2026
- EPSS
- 0.4% · 36th percentile
- CWE
- CWE-824
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
39
Monitor
Low priority for now.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; 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 helpAffected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (mozilla). Independent of NVD's CPE analysis and usually ahead of it.
Mozilla Firefox
- 140.17 and later · up to and including 140.*not affected · rpm
- 153.4 and later · up to and including 153.*not affected · rpm
- 157 and laternot affected · rpm
Mozilla Thunderbird
- 140.17 and later · up to and including 140.*not affected · rpm
- 153.4 and later · up to and including 153.*not affected · rpm
- 157 and laternot affected · rpm
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | firefox-esr | before 153.4.0esr-1~deb12u1 | 153.4.0esr-1~deb12u1 |
| Debian:12 | thunderbird | before 1:140.17.0esr-1~deb12u1 | 1:140.17.0esr-1~deb12u1 |
| Debian:13 | firefox-esr | before 153.4.0esr-1~deb13u1 | 153.4.0esr-1~deb13u1 |
| Debian:13 | thunderbird | before 1:140.17.0esr-1~deb13u1 | 1:140.17.0esr-1~deb13u1 |
| Debian:14 | firefox-esr | before 153.4.0esr-1 | 153.4.0esr-1 |
| Debian:14 | thunderbird | before 1:153.4.0esr-1 | 1:153.4.0esr-1 |
Same product
mozilla: all recordsOther highest-scoring records for the same primary product.
- CVE-2010-3765Mozilla 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 befKEV94Now
- 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
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:firefox-esr | 153.4.0esr-1~deb12u1 · Debian:12 | Package registry (OSV) |
| debian:firefox-esr | 153.4.0esr-1~deb13u1 · Debian:13 | Package registry (OSV) |
| debian:thunderbird | 1:140.17.0esr-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
- Published
- Fix recorded+2 d
- TodayOct 9, 2026+10 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.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-2785217 days apartInvalid pointer in the JavaScript Engine component39Monitor
- CVE-2026-2805217 days apartInvalid pointer in the DOM: Core & HTML component39Monitor
- CVE-2026-1640970 days apartInvalid pointer in the Security: PSM component30Monitor
- CVE-2026-6757161 days apartInvalid pointer in the JavaScript: WebAssembly component25Monitor
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1215 · Sep 30, 2026(Mozilla Firefox Güvenlik Bildirimi)
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-824 · Access of Uninitialized PointerCVSS 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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- CVSS— → 9.8
- Severity— → critical
- SSVC exploitation— → none
- Fix✗ → ✓
- Exploit maturity— → none
For records you follow, these changes also arrive as notifications. →
References
- bugzilla.mozilla.org/show_bug.cgi?id=2072413
- www.mozilla.org/security/advisories/mfsa2026-100/
- www.mozilla.org/security/advisories/mfsa2026-101/
- www.mozilla.org/security/advisories/mfsa2026-102/
- www.mozilla.org/security/advisories/mfsa2026-103/
- www.mozilla.org/security/advisories/mfsa2026-97/
- www.mozilla.org/security/advisories/mfsa2026-99/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.