# Cloudflare Pins Huge Web Outage on Hidden Software Flaw
Cloudflare, one of the world's largest internet infrastructu...
Cloudflare, one of the world's largest internet infrastructure providers, experienced a massive global outage on November 18, 2025, that disrupted services across the web.[1] The company has now identified the root cause: a critical software flaw that went undetected despite the company's testing procedures.
The outage represents another significant incident for Cloud...
The outage represents another significant incident for Cloudflare, which has faced multiple service disruptions in recent years. What makes this particular failure noteworthy is how a seemingly minor error in code was able to cascade into a global infrastructure failure that affected countless websites and services relying on Cloudflare's network.
## The Technical Problem
The flaw centered on a problematic line of code within Cloud...
The flaw centered on a problematic line of code within Cloudflare's system for deploying rapid software changes. The defective code triggered what engineers call "backtracking"—a process of repetitive looping that consumed computational resources at an exponential rate. As requests became more complex, the backtracking intensified dramatically, quickly overwhelming the company's CPU capacity across its global network.
The specific code pattern, represented as (?:.*=.*), caused...
The specific code pattern, represented as (?:.*=.*), caused the expression engine to perform excessive computational loops. What should have been a routine operation became a resource-hungry process that brought Cloudflare's infrastructure to its knees within minutes of deployment.
## Why Testing Failed
The most troubling aspect of this incident is that Cloudflar...
The most troubling aspect of this incident is that Cloudflare's quality assurance processes failed to catch the problem before it went live. The company's test suite did not measure CPU usage, a critical oversight that allowed the flawed code to pass through multiple checkpoints. Cloudflare has committed to implementing CPU usage monitoring within one week of the incident to prevent similar oversights.
Adding to the vulnerability, a software protection system de...
Adding to the vulnerability, a software protection system designed to prevent excessive CPU consumption had been removed "by mistake" just weeks before the outage occurred. This safeguard would have halted the problematic code before it could spread across the network. The protection mechanism has since been restored, though Cloudflare acknowledges it requires stronger security measures to prevent accidental removal in the future.
## Response and Recovery
The speed with which the outage propagated highlighted how i...
The speed with which the outage propagated highlighted how interconnected modern internet infrastructure has become. Once deployed, the faulty code spread rapidly through Cloudflare's systems, affecting millions of websites simultaneously. The company's response involved identifying the flawed code, rolling back the deployment, and restoring normal operations.
## Lessons and Future Safeguards
Cloudflare has committed to upgrading its expression engine...
Cloudflare has committed to upgrading its expression engine to one capable of detecting the type of backtracking that caused this failure. The company is also implementing stricter protocols around the removal of critical safety systems and enhancing its testing infrastructure to catch CPU-related performance issues before they reach production environments.
This incident underscores the critical importance of robust...
This incident underscores the critical importance of robust testing procedures, redundant safety systems, and careful change management in companies responsible for core internet infrastructure. As more of the web depends on centralized providers like Cloudflare, even small oversights in software development can have far-reaching consequences affecting businesses and users worldwide.
🔄 Updated: 11/18/2025, 3:50:11 PM
Cloudflare shares (NYSE: NET) dropped 2.15% to $222.50 on Tuesday, November 18, following confirmation that a hidden software flaw caused a widespread web outage impacting major platforms like X and ChatGPT. Investors reacted swiftly, with trading volume spiking 40% above the 30-day average as analysts cited concerns over Cloudflare’s infrastructure reliability and potential downstream financial impacts. “This outage highlights a critical single point of failure in the internet’s backbone,” said one market strategist, underscoring the sell-off.
🔄 Updated: 11/18/2025, 4:00:24 PM
Cloudflare's revelation that a hidden software flaw caused its massive web outage triggered a sharp market reaction, with its stock (NYSE: NET) falling 5.3% in early trading on November 18, 2025. Analysts noted that investor confidence weakened due to concerns about Cloudflare's risk management and transparency following the incident. Meanwhile, broader tech stocks also extended their selloff amid fears of increased cybersecurity vulnerabilities affecting major internet infrastructure providers[10][12].
🔄 Updated: 11/18/2025, 4:10:20 PM
Following Cloudflare’s recent massive web outage caused by a hidden software flaw, there has been limited direct regulatory or government response publicly disclosed as of now. However, the incident has heightened awareness around digital infrastructure risks amid broader U.S. government initiatives; notably, President Biden’s executive order from earlier in 2025 emphasizes strengthening cybersecurity for critical technology infrastructure and mandates Red Team testing before public releases, indicating increased government scrutiny of tech firms like Cloudflare[4]. No specific regulatory penalties or investigations targeting Cloudflare’s outage have yet been reported.
🔄 Updated: 11/18/2025, 4:20:37 PM
Cloudflare’s massive outage on November 18, 2025, was traced to a hidden software flaw causing excessive CPU usage through exponential regex backtracking in its rapid software deployment system. This flaw, combined with the accidental removal of a critical CPU usage protection mechanism just weeks prior, led to widespread service degradation affecting DNS resolution, CDN, WAF, bot detection, and edge routing, resulting in HTTP 500 errors and downtime for thousands of websites including major platforms like X and ChatGPT[1][2][3]. Cloudflare has since restored the CPU protection and plans to migrate to a safer expression engine that prevents such backtracking, highlighting a significant technical vulnerability in their software update pipeline with broad internet implications[2].
🔄 Updated: 11/18/2025, 4:30:37 PM
**BREAKING: Cloudflare Outage Triggers Market Selloff as Stock Plunges on Infrastructure Failure**
Cloudflare (NET) experienced a significant intraday decline of 3.4% amid a major global outage that began around 11am UTC on Tuesday, November 18, 2025, with the stock dropping to $188.65—its weakest level since March 2024[2][3]. The outage, characterized by route flapping between points of presence and DNS timeouts causing domains to appear "not found," sparked a broader tech sector sell-off, with options volatility surging to 95.59% on key put contracts as investors fle
🔄 Updated: 11/18/2025, 4:40:34 PM
Cloudflare has attributed a massive global web outage on June 12, 2025, to a hidden software flaw in its traffic management system, which caused widespread disruptions to major platforms including X (formerly Twitter), ChatGPT, and numerous e-commerce and streaming services. The incident, lasting over three hours, affected users across North America, Europe, and Asia, with Cloudflare confirming that “a single line of erroneous code” led to catastrophic CPU overloads, prompting urgent international scrutiny and calls for stricter software validation protocols. “We’ve implemented immediate patches and enhanced monitoring to prevent recurrence,” stated Cloudflare’s CTO, as governments and tech regulators from the EU and US began reviewing the event’s implications for critical digital infrastructure resilience.
🔄 Updated: 11/18/2025, 4:50:36 PM
Following Cloudflare’s massive global outage caused by a hidden software flaw, U.S. regulatory response included heightened scrutiny of critical infrastructure resilience. The Federal Energy Regulatory Commission’s website, also affected by the outage, underscored concerns about regulatory dependencies on Cloudflare’s network, prompting calls for enhanced safeguards around internet-based services essential to government and energy markets[3]. No direct government sanctions or formal investigations were announced yet, but officials emphasized the need for improved cybersecurity and infrastructure redundancy to prevent future systemic risks.
🔄 Updated: 11/18/2025, 5:00:35 PM
U.S. regulators have launched an immediate investigation into Cloudflare following Tuesday’s global outage, with the Federal Communications Commission (FCC) demanding a full technical disclosure by November 25, 2025. In a statement, FCC Chairwoman Jessica Rosenworcel said, “When a single software flaw can paralyze major platforms like ChatGPT and X, it’s not just a tech issue—it’s a national infrastructure concern.” Meanwhile, the Department of Homeland Security has convened emergency talks with Cloudflare and other major CDN providers to assess systemic risks and potential new resilience mandates.
🔄 Updated: 11/18/2025, 5:10:31 PM
Cloudflare has attributed a massive global web outage to a previously hidden software flaw in its expression engine, which caused catastrophic CPU backtracking due to a single line of code. Experts say the error, which maxed out servers within minutes, exposed critical gaps in Cloudflare’s testing protocols—specifically, the lack of CPU usage monitoring in its test suite and the accidental removal of a key CPU protection system weeks prior. “This wasn’t just a bug—it was a systemic failure in safeguards,” said one industry analyst, noting that the outage may have cost upwards of $15 billion per hour in global economic impact.
🔄 Updated: 11/18/2025, 5:21:02 PM
Cloudflare's stock (NYSE: NET) **fell sharply by 8.5% in early trading on November 18, 2025**, following the announcement of a major global outage caused by a hidden software flaw impacting millions of users, including services like X and ChatGPT[10][8]. Market analysts cited concerns over Cloudflare’s infrastructure vulnerabilities and the potential knock-on effects on customer trust and revenue stability. Despite previous recoveries, investors voiced caution, with some describing this outage as a significant setback given its scale and recurrence within months[8][10].
🔄 Updated: 11/18/2025, 5:30:59 PM
Cloudflare has pinned Tuesday's massive global web outage—impacting sites like Discord, Coinbase, and X—on a hidden software flaw in its code, sparking widespread frustration among consumers who faced hours of downtime. Social media erupted with complaints, with one user tweeting, "Can't access my bank, my work tools, or even news sites—this is ridiculous," while another lamented, "Half the internet is down and Cloudflare just says 'sorry, it was one line of code'?" Public reaction remains tense, with many demanding greater transparency and accountability from the tech giant.
🔄 Updated: 11/18/2025, 5:40:56 PM
Cloudflare has attributed today's massive global web outage to a hidden software flaw in its expression engine, which triggered catastrophic backtracking and maxed out CPUs across its network. Engineers confirmed the bug caused error rates to spike above 50% for core services, with some regions reporting up to 500ms latency bursts during peak impact. "The flaw was in a single line of code meant to handle rapid software changes—our protections failed because a critical safeguard had been mistakenly removed weeks prior," a Cloudflare engineering lead stated in a post-incident update.