Oh Dear Finds 18.8% of Monitored Sites Down at the Peak of the October PHP Incident

More than 40 hours later, the share of sites down was still more than twice the level measured a week earlier.

BERLAAR, ANTWERP, BELGIUM, October 26, 2026 /EINPresswire.com/ — In the half hour beginning at 14:30 UTC on 21 October 2026, 18.8% of the websites monitored by Oh Dear were down. In the same half hour a week earlier, 0.9% were. The spike followed the public disclosure of two PHP vulnerabilities, CVE-2026-109618 and CVE-2026-109619.

Many PHP site owners took their applications offline while they waited for patches, Oh Dear wrote on 22 October. Oh Dear continues checking during planned maintenance and counts sites as down when they meet its failed-check threshold.

The charts, the half-hour data and the full method are in the October incident section of Oh Dear’s uptime statistics. They cover tens of thousands of sites with HTTP checks between 20 and 23 October, compared with the same hours a week earlier.

A slow return to normal
Five hours after the peak, 8.9% of monitored sites were down. At 07:30 UTC on 23 October, 41 hours after the peak, the figure was 2%, compared with 0.9% at that time the previous week. Each figure is a snapshot of one half hour. Different sites may have been down at each point.

Over the three days, 11.3% of monitored sites had an outage lasting 4 to 12 hours. In the comparison week, 0.1% did.

At the peak, 43.4% of the sites that were down returned HTTP 503, up from 7.7% before the incident. Maintenance pages usually send that code. On its own, the code does not show why a site was offline or whether someone took it down on purpose.

Earlier research on ordinary outages
In June, Oh Dear published research on 1,817,403 confirmed outages recorded between March and December 2025. Half of them ended within two minutes, and the median was 1.9 minutes. The June median describes individual outage durations; the October peak describes the share of monitored sites down in one half hour.

Methodology
The sample is every site with an HTTP uptime check from 20 October at 09:00 UTC to 23 October at 08:00 UTC. A site counts as down in a half hour when at least half of its checks fail. The comparison is the same hours from 13 to 16 October. Planned maintenance counts as down when checks fail. A majority of the sites Oh Dear monitors are PHP sites. This is not a measure of all websites, or of all PHP websites.

About Oh Dear
Oh Dear monitors the health of every website you manage. Oh Dear checks uptime every minute and monitors SSL, DNS, domains, cron jobs, broken links, performance and application health. Oh Dear includes actionable alerts and branded status pages.

Deian Isac
Oh Dear
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