CVE-2026-8706 | Sensitive user data could be leaked to other applications through Reader mode

Firefox for iOS hosted Reader mode on an unauthenticated local web server, allowing another application on the same device to request arbitrary URLs and receive the response rendered with the signed-in user's cookies. This vulnerability was fixed in Firefox for iOS 151.0.

Published: 2026-05-19 Last update: 2026-05-20 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-8706 is rated Low Risk (27.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-8706

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-20 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-8706

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-8706

GitHub Security Advisory for CVE-2026-8706

GHSA-4c2h-7p75-v7hg · Severity: medium — Firefox for iOS hosted Reader mode on an unauthenticated local web server, allowing another...

OS Trackers for CVE-2026-8706

vendor priority summary link
suse high — https://www.suse.com/security/cve/CVE-2026-8706/
ubuntu medium CVE-2026-8706 medium priority: Ubuntu including 9 source packages (firefox, mozjs102, …), 49 status rows across 7 suites (bionic, focal, jammy, noble, questing, resolute, upstream): DNE 23, not-affected 18, ignored 8. https://ubuntu.com/security/CVE-2026-8706

Affected software / configurations for CVE-2026-8706

Vendor Product Version Raw CPE
mozilla firefox < 151.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:iphone_os:*:*

References for CVE-2026-8706

cvelogic Threat Intelligence