CVE-2020-12404 — For native-to-JS bridging the app requires a unique token to be passed that ensu

For native-to-JS bridging the app requires a unique token to be passed that ensures non-app code can't call the bridging functions. That token could leak when used for downloading files. This vulnerability affects Firefox for iOS < 26.

01What is this vulnerability?

For native-to-JS bridging the app requires a unique token to be passed that ensures non-app code can't call the bridging functions. That token could leak when used for downloading files. This vulnerability affects Firefox for iOS < 26.

02Affected products

No structured affected-product list available — see references below for vendor advisories.

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2020-07-09T15:15:10.880
• Last modified: 2026-08-19T15:30:33.807

09References

• bugzilla.mozilla.org — https://bugzilla.mozilla.org/show_bug.cgi?id=1631739
• www.mozilla.org — https://www.mozilla.org/security/advisories/mfsa2020-19/
• bugzilla.mozilla.org — https://bugzilla.mozilla.org/show_bug.cgi?id=1631739
• www.mozilla.org — https://www.mozilla.org/security/advisories/mfsa2020-19/