# Actively Exploited WordPress Core Flaw Lets Hackers Run Code During Updates, CISA Warns

*Wednesday, November 4, 2026 at 6:14 AM UTC — Hamer Intelligence Services Desk*

**Published**: 2026-11-04T06:14:27.724Z (3h ago)
**Category**: cyber | **Region**: Global
**Importance**: 8/10
**Sources**: OSINT
**Permalink**: https://hamerintel.com/data/articles/22436.md
**Source**: https://hamerintel.com/summaries

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**Deck**: Attackers are exploiting a high-severity race condition in WordPress Core, tracked as CVE-2026-119977, that enables unauthenticated code execution during core upgrades. CISA has confirmed live attacks, and one security report logged more than 12,600 blocked exploit attempts in 24 hours.

A serious security flaw in WordPress Core is being actively exploited, raising the risk that attackers can quietly take control of websites during routine software updates.

The bug, identified as CVE-2026-119977, arises from a race condition during WordPress core upgrades. In practice, there’s a brief period while a site is updating when key files are changing. The vulnerability allows an attacker to trigger that window and inject their own code so it runs on the server, without needing valid login credentials.

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has confirmed that attacks targeting this flaw are under way. A security report cited on 4 November recorded more than 12,600 exploit attempts blocked in a single day, indicating that automated scans and broad attacks have already started.

Because WordPress underpins a large share of the public web, a core vulnerability like this carries systemic implications. A successful exploit can let an intruder alter site content, harvest user data or gain broader access to the underlying server that hosts the site.

One of the challenges for defenders is that an attack timed to coincide with an upgrade may not leave obvious signs. If a backdoor or modified configuration file is planted during that short update phase, the site may appear to function normally while it’s being used for phishing, malware delivery or data theft.

For everyday users, a compromised WordPress site can act as a trusted-looking lure. Visitors may be nudged into handing over credentials or downloading malicious files, believing they’re interacting with a familiar blog, business or institutional page.

The wave of exploit attempts reported so far shows that the issue has moved beyond test code and into broad, real-world use by attackers. Security teams now need to identify which of their assets run WordPress, apply any available fixes or mitigations, and inspect logs around recent upgrade operations for suspicious activity.

Key signals in the near term will be the release and uptake of patched WordPress core versions, guidance from major hosting providers, and any move by CISA to place CVE-2026-119977 on its formal list of known exploited vulnerabilities, which would trigger specific deadlines for U.S. federal agencies to remediate affected systems.