CVE-2026-8971
Same-origin policy bypass in the Networking: JAR component
MEDIUM
6.5
CVSS Score
Published: May 19, 2026 at 12:30 PM UTC
Updated: July 23, 2026 at 09:11 PM UTC
2 products affected across 1 vendorFirefoxThunderbird
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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit
Description
Same-origin policy bypass in the Networking: JAR component. This vulnerability was fixed in Firefox 151.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
v < 151.0.0
Vendor states this is fixed in 151 (unaffected)
Affected range stops below 151.0.0, so it looks safe — our inference, not a vendor statement
v < 151.0.0
Vendor states this is fixed in 151 (unaffected)
Affected range stops below 151.0.0, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
References (3)
SSVC — Action Prioritization
SSVCNo known exploitAutomatablePartial impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
6.5MEDIUMCISA-ADP
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- LOW
- Integrity
- LOW
- Availability
- NONE
Vector?
Quick Info
StatusANALYZED
CWE
CWE-346
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