A widely discussed post on r/WordPress, shared by Reddit user JoseDieguez, warns that some websites updating to WordPress 6.9 are experiencing sudden, persistent spikes in CPU usage reaching 100%. Although initial reports sparked concerns of a core-level performance regression, further investigation suggests the issue is not widespread and is likely tied to a specific theme or plugin incompatibility, most notably the WoodMart theme.
Early Reports Suggested a Severe Problem
According to JoseDieguez, multiple production sites on his hosting infrastructure experienced the same pattern immediately after updating:
- CPU usage jumping from ~10–20% to 90–100%
- No increase in traffic
- Load is returning to normal only after downgrading to WordPress 6.8.3
This prompted a warning urging site owners to delay automatic updates until more was known.
Updated Findings: Issue Appears Isolated
As the day progressed, the post was updated with new details:
- Dozens of other sites have been successfully upgraded with no issues.
- Only four sites (out of more than 50 monitored) showed a CPU spike.
- All affected sites were running the WoodMart theme.
- Other users on Reddit later confirmed similar correlations.
This strongly suggests the issue is not caused by WordPress 6.9 itself, but triggered when the new release interacts with certain theme/plugin setups. WoodMart has been the most consistent common denominator so far.
Community Feedback: Most Users Report No Problems
The Reddit thread contains dozens of responses from developers and hosts managing tens or even hundreds of sites:
- Many reported zero performance issues after updating.
- Several emphasized that major updates should be thoroughly tested on a staging environment.
- Others noted that sites with heavy content and numerous plugins are typically the first to expose compatibility conflicts.
A few users experiencing the issue echoed the pattern of high MySQL usage, heavy loops, or runaway background tasks; however, the cases were limited.
Suspected Culprit: WoodMart Core
Multiple commenters pointed to existing support threads indicating a compatibility issue between:
- WoodMart Core plugin
- WPBakery Page Builder
- WordPress 6.9
Links to related support discussions were shared, reinforcing the likelihood of a theme-level conflict.
Current Recommendation
Based on the reporting:
- The CPU issue is not global.
- Most sites run WordPress 6.9 without incident.
- If you use WoodMart, hold off on updating until the theme developer issues a fix.
- For any site impacted, rolling back to WordPress 6.8.3 resolves the issue immediately.
Bottom Line
While the initial warning sounded serious, the evidence now suggests a localized compatibility issue, rather than a systemic failure in WordPress 6.9. Still, the incident serves as a strong reminder of the best practices echoed throughout the thread: always test major core updates on a staging environment, especially for high-traffic or plugin-heavy production sites.
Source: https://old.reddit.com/r/Wordpress/comments/1pd35y4/wordpress_69_is_causing_permanent_100_cpu_usage/