FirefoxWeb browser · Mozilla
CVE-2026-8706
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedFirefox 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceFirefox for iOS ran an unauthenticated local HTTP server to serve Reader mode content, allowing any other app on the same iOS device to send requests through this local server and receive responses with the user's authenticated cookies. This constitutes a local app-to-app cookie theft vulnerability bypassing app isolation.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FirefoxWeb browser
< 151.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Firefox for iOS installed versionOpen the App Store app, go to the Updates tab, and locate Firefox for iOS to see the current version. Alternatively, open Firefox, tap the menu icon, go to Settings, then About Firefox to view the version number.Affected if version number is below 151.0 (for example, 150.3 or earlier)
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Determine if Reader mode was ever usedOpen Firefox for iOS and look for the reader mode icon (typically a document icon) in the address bar when visiting articles, or check browser history for articles that may have been opened in reader mode.Affected if Reader mode was accessed on a device running Firefox for iOS version below 151.0, as this activates the vulnerable local HTTP server
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Assess local app presence on deviceReview the list of installed applications on the iOS device through the Home screen or Settings > General > iPhone Storage to identify any third-party or unfamiliar apps.Affected if Any third-party local application is installed on the device alongside a vulnerable Firefox for iOS version, as such an app could make requests to the local HTTP server
A user is affected if Firefox for iOS version is below 151.0 and Reader mode was accessed, since any local app could exploit the unauthenticated HTTP server to steal session cookies.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped151.0
Update Firefox for iOS to version 151.0 or later. Organizations should verify end-user devices have the patched version installed.
Firefox for iOS 151.0
- Open the App Store on the iOS device
- Search for Firefox for iOS or locate it in your installed apps
- If installed version is below 151.0, tap Update to upgrade to version 151.0 or later
- Alternatively, enable automatic app updates in iOS Settings > App Store > Automatic Downloads to ensure future security updates are applied
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Firefox
Scoped from the published advisory
- Consultation3.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,304.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-8706 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-8706 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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