Firefox iOS flaw enables remote denial-of-service
A vulnerability in Firefox for iOS versions before 155.1 allows a remote attacker to trigger a denial-of-service condition.
Sourcecert.ssi.gouv.fr — open the original
What to check
- Applies to
- The 1 CVE named below. Whether you run an affected version is not assessed: check the versions the source lists.
- Exploitation
- No exploitation in the wild and no public exploit is recorded for the CVEs named.
ANSSI (CERT-FR) has published an advisory relaying a Mozilla security bulletin (MFSA2026-89) describing a vulnerability in Firefox for iOS affecting all versions prior to 155.1. The flaw allows a remote attacker to cause a denial-of-service condition, though the advisory provides no evidence of active exploitation and no further technical detail beyond the CVE reference and affected version range.
Mozilla has released a patch in version 155.1 that addresses the issue. Organizations and users running affected versions of Firefox for iOS should update to the fixed version as soon as practical, referencing the vendor's security advisory for details. No indicators of compromise, threat actor attribution, or exploitation-in-the-wild reports are associated with this bulletin.
Mentioned in this report
Source reporting: https://www.cert.ssi.gouv.fr/avis/CERTFR-2026-AVI-1142
Free public brief. Slack alerts on the vendors you run come with the paid plans, and a new account gets three days of them, no card.
What this brief leaves out
This page is the free tier: the write-up, the severity, the names. In the app the same report carries live profiles of the CVEs it names. The paid plans add the security research and news reporting the free tier leaves out.
It sits in a corpus of 16,445 reports from 149 sources, 666 of them written in the last seven days, and it grows through the day.
A new account starts with three days of all of it, no card, then keeps the government and CERT reporting free. Slack alerts are a paid-plan feature: name the vendors you run and Slack hears about the reports that touch them, not the rest of the week's. Nothing is charged unless you subscribe.
Create a free account What it costs