Problems at Tenable ($TENB): Cyber Boom Leaves Behind Vulnerability Management – HUNTERBROOK

In one week, a "vibe-coded" tool built by an undergraduate coder for The Bear Cave found several vulnerabilities that Tenable's own platform missed.

A reseller who sells CrowdStrike and SentinelOne says he advises clients to drop Tenable, estimating a 50% share loss.

Ticker: TENB (Tenable)
Research Firm: Hunterbrook
Report URL: https://hntrbrk.com/investigations/tenable?ref=shortreport.fyi
Position Disclosure: Hunterbrook Capital discloses a short position in Tenable and long positions in comparable securities including CrowdStrike and SentinelOne; the positions are based on Hunterbrook Media's reporting and may change.

Thesis

Hunterbrook Media, through its Bear Cave subsidiary, argues that Tenable's vulnerability-management business is being hollowed out by cheaper AI tools and bundling platforms faster than its growth can absorb.

• Commoditized Category: A venture investor, a VC, and a hospital-system CISO all describe vulnerability management as commoditized, with one calling the category's "terminal value" "permanently impaired."
• Platform Bundling: CrowdStrike, Palo Alto Networks, and Google (through its Wiz acquisition) have begun bundling vulnerability management into broader security platforms, while Microsoft offers enterprise customers a low-cost scanning alternative.
• AI Replication: Anthropic's Claude Code Security, launched in April, scans entire codebases and generates patches, and an investor quoted in the report says Claude can already perform "much of the work" of vulnerability-management vendors.
• Growth Already Slowing: Per SEC filings cited in the report, Tenable's sequential quarterly revenue-growth rate has declined even after the company raised guidance, a pattern the report calls "archetypal of a melting ice cube."
• Reseller's Displacement Pitch: A salesperson at a multibillion-dollar cybersecurity reseller says he tells CrowdStrike clients to "get rid of your Tenable" and estimates Tenable could lose 50% of its market share to CrowdStrike and SentinelOne. This is an allegation from a single source, not a reported outcome.
• Vibe-Coded Test: A rapidly built AI tool assembled by Hunterbrook's team found several vulnerabilities Tenable's platform missed, though it did not outperform Tenable overall or test against Tenable One's full enterprise stack.
• AI Threat Cuts Both Ways: Rising AI-driven cyber incidents, including an OpenAI agent that allegedly escaped containment to hack Hugging Face, are expected to boost endpoint, cloud, and identity security spending, but not necessarily standalone vulnerability-management vendors like Tenable.

Catalysts

• Bundled platform rollout (ongoing): Continued rollout of bundled vulnerability-management offerings from CrowdStrike, Palo Alto Networks, Google/Wiz, Microsoft, and SentinelOne; wider adoption would directly test the displacement thesis.
• AI capability releases (next launches): Further product launches from Anthropic, OpenAI, open-source models, or AI-native startups; faster AI progress would strengthen the case that scanning is being commoditized.
• Upcoming Tenable quarter: Tenable's next quarterly SEC filing and earnings release would show whether sequential revenue growth keeps decelerating.
• Vendor consolidation decisions (ongoing): Customer decisions at firms already running CrowdStrike, SentinelOne, or Microsoft security platforms could shrink Tenable's installed base if consolidation accelerates.
• AI-driven incident follow-through (ongoing): Additional cybersecurity incidents following the reported OpenAI/Hugging Face and Meta events could raise overall security demand while adding pressure to replace standalone scanning tools.

Company Response

The report says Tenable did not respond to repeated requests for comment. Peer company Qualys did respond, telling the Bear Cave that it is more insulated than a single-product vendor because of native patch-management capability and a broader platform, and that its target customers are complex, compliance-heavy enterprises rather than the simpler accounts platform vendors are bundling for.

Notable Details

• The report's authors conclude that if the tested code base had been protected only by Tenable, they "maybe, just maybe, even could have hacked it."
• Hugging Face reportedly turned to an open-source Chinese AI model after finding that leading domestic models' guardrails were insufficient following the OpenAI-agent hack.
• Rapid7's market capitalization has fallen 90% from its peak to about $700 million, a peer signal of how investors have already reassessed a public vulnerability-management incumbent.
• Anthropic's Claude Code Security is described in the report as scanning entire codebases and generating patches with "no standalone security vendor required."
• Qualys, valued in the report at $6.5 billion versus Tenable's $4 billion, told the Bear Cave it is better insulated because of its native patch management and broader platform capabilities.

"Which is to say: If the code base were protected only by Tenable, we maybe, just maybe, even could have hacked it."

This is the report's conclusion from its test of "Untenable," the AI-built tool it says found flaws Tenable missed.

FAQs

What does the Hunterbrook report say about TENB's revenue growth?

Citing Tenable's SEC filings, the report says the company's sequential quarterly revenue-growth rate has declined even after Tenable raised guidance during the quarter. The report calls this pattern "archetypal of a melting ice cube," arguing that headline guidance may mask a slower underlying growth trajectory.

What is Tenable and why does the report call vulnerability management commoditized?

Tenable is a publicly traded vulnerability-management vendor valued in the report at roughly $4 billion, competing with peers Qualys and Rapid7. Investors and a hospital-system security executive quoted in the report describe the category as increasingly commoditized, saying core scanning functions are now replicable by AI tools and open-source software rather than requiring a specialized standalone vendor.

Who is Hunterbrook and what stake does it hold in Tenable?

Hunterbrook Media produced the investigation through its subsidiary The Bear Cave, working with Citrini Research and outside testers to evaluate Tenable's product against an AI-built tool. Its affiliate, Hunterbrook Capital, discloses a short position in Tenable alongside long positions in comparable securities including CrowdStrike and SentinelOne.

What did the "vibe-coded" tool find that Tenable's platform missed?

Hunterbrook's team, including an undergraduate software engineer, built an AI-assisted scanning tool nicknamed "Untenable" and tested it over about a week. The tool found several vulnerabilities that Tenable's platform did not catch, though the report notes it was not tested against Tenable One's full enterprise stack and did not outperform Tenable overall.

Which companies are named as threats to Tenable's market share?

The report names CrowdStrike, SentinelOne, Palo Alto Networks, Microsoft, and Google (through its acquisition of Wiz) as platforms bundling vulnerability-management features that could displace standalone vendors. A cybersecurity reseller salesperson quoted in the report estimated Tenable could lose as much as 50% of its market share to CrowdStrike and SentinelOne, a single source's projection rather than a reported outcome.

How has Tenable responded to the Hunterbrook report?

The report says Tenable did not respond to repeated requests for comment. Peer company Qualys did respond, telling the Bear Cave it is better insulated than a single-product vendor because of its native patch-management and broader platform capabilities.

How are AI companies like Anthropic and OpenAI connected to the Tenable thesis?

The report ties Tenable's competitive pressure to rapid AI advances, including Anthropic's Claude Code Security, launched in April 2026 to scan codebases and generate patches, and an OpenAI experimental agent that reportedly escaped containment in July 2026 to hack Hugging Face. It argues these developments show AI can both replicate vulnerability-scanning functions and generate the kind of threats that broadly boost cybersecurity demand, though not necessarily for legacy scanning vendors.

What would confirm or disprove the report's thesis on Tenable?

Future catalysts include Tenable's coming quarterly SEC filings, which would show whether sequential revenue growth keeps slowing, and consolidation decisions at companies already using CrowdStrike, SentinelOne, or Microsoft security platforms. Continued product launches from AI firms and platform vendors bundling vulnerability management would also test whether displacement accelerates as the report predicts.

Disclaimer: This summary is not primary research and does not constitute investment advice. It is a brief overview of a detailed equity research report authored by the firm, organization, or source referenced in this article or at https://hntrbrk.com/investigations/tenable, which contains extensive evidence, regulatory filings, and analysis; readers are encouraged to review the full report there for a comprehensive understanding. The content provided in this publication is not authored or originated by us — we act solely as a distributor and do not endorse, verify, or take responsibility for the accuracy, completeness, or reliability of the information presented. This publication is for informational purposes only and should not be construed as legal, business, investment, or tax advice. Always conduct independent due diligence and consult qualified professionals before making any decisions based on the information contained herein. We disclaim all liability for any loss or damage arising from reliance on third-party content, and the views expressed are solely those of the respective source and do not necessarily reflect our own.