Same-origin policy bypass in the Request Handling component
Same-origin policy bypass in the Request Handling component. This vulnerability was fixed in Firefox 146, Firefox ESR 115.31, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.
- BDU:2025-16360
- ALSA-2025:23034
- ALSA-2025:23035
- ALSA-2025:23128
- ALSA-2025:23856
- ALSA-2026:0025
- ALSA-2026:0026
- DLA-4401-1
- DLA-4405-1
- DSA-6078-1
- DSA-6081-1
- openSUSE-SU-2025:15809-1
- openSUSE-SU-2025:15813-1
- openSUSE-SU-2025:15814-1
- openSUSE-SU-2026:20014-1
- openSUSE-SU-2026:20046-1
- RHSA-2025:23034
- RHSA-2025:23035
- RHSA-2025:23128
- RHSA-2025:23856
- Published
- Dec 9, 2025
- Updated
- Sep 30, 2026
- EPSS
- 0.2% · 7th percentile
- CWE
- CWE-346
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Report tools
Action score
26
Monitor
Low priority for now.
- CVSS
- 26 / 40 · 6.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 6.5
- CNA · mozilla
- 6.5
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| mozilla | firefox | cpe:2.3:a:mozilla:firefox |
| mozilla | thunderbird | cpe:2.3:a:mozilla:thunderbird |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- mozilla firefoxbefore 115.31.0
- mozilla firefoxbefore 146.0
- mozilla firefox116.0 and later · before 140.6.0
- mozilla thunderbirdbefore 140.6.0
- mozilla thunderbirdbefore 146.0
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
- 115.31 and later · up to and including 115.*not affected · rpm
- 140.6 and later · up to and including 140.*not affected · rpm
- 146 and laternot affected · rpm
Mozilla Thunderbird
- 140.6 and later · up to and including 140.*not affected · rpm
- 146 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 |
|---|---|---|---|
| AlmaLinux:10 | firefox | before 140.6.0-1.el10_1 | 140.6.0-1.el10_1 |
| AlmaLinux:10 | thunderbird | before 140.6.0-1.el10_1.alma.1 | 140.6.0-1.el10_1.alma.1 |
| AlmaLinux:8 | firefox | before 140.6.0-1.el8_10.alma.1 | 140.6.0-1.el8_10.alma.1 |
| AlmaLinux:8 | thunderbird | before 140.6.0-1.el8_10.alma.1 | 140.6.0-1.el8_10.alma.1 |
| AlmaLinux:9 | firefox | before 140.6.0-1.el9_7.alma.1 | 140.6.0-1.el9_7.alma.1 |
| AlmaLinux:9 | firefox-x11 | before 140.6.0-1.el9_7.alma.1 | 140.6.0-1.el9_7.alma.1 |
| AlmaLinux:9 | thunderbird | before 140.6.0-1.el9_7.alma.1 | 140.6.0-1.el9_7.alma.1 |
| Debian:11 | firefox-esr | before 140.6.0esr-1~deb11u1 | 140.6.0esr-1~deb11u1 |
| Debian:11 | thunderbird | before 1:140.6.0esr-1~deb11u1 | 1:140.6.0esr-1~deb11u1 |
| Debian:12 | firefox-esr | before 140.6.0esr-1~deb12u1 | 140.6.0esr-1~deb12u1 |
| Debian:12 | thunderbird | before 1:140.6.0esr-1~deb12u1 | 1:140.6.0esr-1~deb12u1 |
| Debian:13 | firefox-esr | before 140.6.0esr-1~deb13u1 | 140.6.0esr-1~deb13u1 |
| Debian:13 | thunderbird | before 1:140.6.0esr-1~deb13u1 | 1:140.6.0esr-1~deb13u1 |
| Debian:14 | firefox-esr | before 140.6.0esr-1 | 140.6.0esr-1 |
| Debian:14 | thunderbird | before 1:140.6.0esr-1 | 1:140.6.0esr-1 |
| openSUSE:Leap 16.0 | MozillaFirefox | before 140.6.0-160000.1.1 | 140.6.0-160000.1.1 |
| openSUSE:Leap 16.0 | MozillaThunderbird | before 140.6.0-bp160.1.1 | 140.6.0-bp160.1.1 |
| openSUSE:Tumbleweed | firefox-esr | before 140.6.0-1.1 | 140.6.0-1.1 |
| openSUSE:Tumbleweed | MozillaFirefox | before 146.0-1.1 | 146.0-1.1 |
| openSUSE:Tumbleweed | MozillaThunderbird | before 140.6.0-1.1 | 140.6.0-1.1 |
| Red Hat:enterprise_linux_eus:10.0 | firefox | before 0:140.6.0-1.el10_0 | 0:140.6.0-1.el10_0 |
| Red Hat:enterprise_linux_eus:10.0 | firefox-debuginfo | before 0:140.6.0-1.el10_0 | 0:140.6.0-1.el10_0 |
| Red Hat:enterprise_linux_eus:10.0 | firefox-debugsource | before 0:140.6.0-1.el10_0 | 0:140.6.0-1.el10_0 |
| Red Hat:enterprise_linux_eus:10.0 | thunderbird | before 0:140.6.0-1.el10_0 | 0:140.6.0-1.el10_0 |
+86
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 |
|---|---|---|
| almalinux:firefox | 140.6.0-1.el9_7.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:firefox-x11 | 140.6.0-1.el9_7.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:thunderbird | 140.6.0-1.el9_7.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| debian:firefox-esr | 140.6.0esr-1~deb12u1 · Debian:12 | Package registry (OSV) |
| debian:thunderbird | 1:140.6.0esr-1~deb12u1 · Debian:12 | Package registry (OSV) |
| opensuse:firefox-esr | 140.6.0-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:MozillaFirefox | 140.6.0-150200.152.213.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| opensuse:MozillaThunderbird | 140.6.0-150200.8.248.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| red hat:firefox | 0:140.6.0-1.el9_7 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:firefox-debuginfo | 0:140.6.0-1.el9_7 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:firefox-debugsource | 0:140.6.0-1.el9_7 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:firefox-x11 | 0:140.6.0-1.el9_7 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:thunderbird | 0:140.6.0-1.el9_7 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:thunderbird-debuginfo | 0:140.6.0-1.el9_7 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:thunderbird-debugsource | 0:140.6.0-1.el9_7 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| rocky linux:firefox | 0:140.6.0-1.el9_7 · Rocky Linux:9 | Package registry (OSV) |
| rocky linux:thunderbird | 0:140.6.0-1.el9_7 · Rocky Linux:9 | Package registry (OSV) |
| suse:MozillaFirefox | 140.6.0-112.292.1 · SUSE:Linux Enterprise Server 12 SP5-LTSS | Package registry (OSV) |
| suse:MozillaFirefox | 140.6.0-150200.152.213.1 · SUSE:Linux Enterprise Module for Desktop Applications 15 SP6 | Package registry (OSV) |
| suse:MozillaThunderbird | 140.6.0-150200.8.248.1 · SUSE:Linux Enterprise Module for Package Hub 15 SP6 | 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.
No dated events beyond publication.
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-2026-279077 days apartSame-origin policy bypass in the Networking: JAR component39Monitor
- CVE-2026-16349224 days apartSame-origin policy bypass in the DOM: Navigation component39Monitor
- CVE-2026-16358224 days apartSite isolation issue in the Graphics: WebRender component39Monitor
- CVE-2026-16375224 days apartSite isolation issue in the Networking: HTTP component39Monitor
- CVE-2026-84129266 days apartSite isolation issue in the DOM: Navigation component39Monitor
- CVE-2026-84140266 days apartSite isolation issue in the DOM: Navigation component39Monitor
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
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-346 · Origin Validation ErrorCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
nvd-primary
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)
- JSON Hijacking (aka JavaScript Hijacking)CAPEC-111likelihood: High · High
- Cache PoisoningCAPEC-141likelihood: High · High
- DNS Cache PoisoningCAPEC-142likelihood: High · High
- Exploit Script-Based APIsCAPEC-160Medium
- Exploitation of Trusted IdentifiersCAPEC-21likelihood: High · High
- Application API Message Manipulation via Man-in-the-MiddleCAPEC-384Low
- Transaction or Event Tampering via Application API ManipulationCAPEC-385Medium
- Application API Navigation RemappingCAPEC-386Medium
ATT&CK techniques
- Access Token ManipulationT1134
- Access Token Manipulation:Token Impersonation/TheftT1134.001
- Steal Application Access TokenT1528
- Steal Web Session CookieT1539
- Use Alternate Authentication Material:Web Session CookieT1550.004
- Adversary-in-the-Middle: ARP Cache PoisoningT1557.002
- Compromise Infrastructure: DNS ServerT1584.002
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
- bugzilla.mozilla.org/show_bug.cgi?id=2000218
- www.mozilla.org/security/advisories/mfsa2025-92/
- www.mozilla.org/security/advisories/mfsa2025-93/
- www.mozilla.org/security/advisories/mfsa2025-94/
- www.mozilla.org/security/advisories/mfsa2025-95/
- www.mozilla.org/security/advisories/mfsa2025-96/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.