Zscaler Sheds 8% as Fortinet's Service Revenue Guidance Rattles Cybersecurity Stocks

Zscaler shares took an 8.0% hit in yesterday's session, dragged down by a weaker-than-expected service revenue outlook from rival Fortinet. The decline stemmed from a competitor's news release rather than any fresh guidance cut from Zscaler itself, with concerns about the broader industry landscape taking center stage.

Fortinet's Forecast Triggers Sector-Wide Selling

Fortinet trimmed its full-year service revenue guidance alongside its third-quarter 2026 results, now projecting $5.150 billion to $5.170 billion. The softer-than-anticipated forecast set off a selloff across the cybersecurity sector, according to media reports.

The fallout spread to other players in the space, and Zscaler was among the stocks caught in the downdraft during after-hours trading, media reports indicated. For investors, the distinction matters: Fortinet's business outlook describes its own trajectory first and foremost. It is not a statement from Zscaler about its own operating condition.

Fortinet simultaneously reported quarterly revenue of $2.08 billion and adjusted diluted earnings per share of $0.91. Despite those results, the negative market reaction zeroed in on the service business outlook.

Zscaler's weakness can thus be framed as part of a broader sector move. The reaction alone does not establish that Zscaler faces the same operational problems or must revise its own expectations.

Certificate Removal Follows eMudhra Reports

On the company-specific front, Zscaler issued its own statement on October 22 addressing reports of compromised TLS intermediate certificates from eMudhra. The company said it had found no evidence of compromise in its own environment.

At the same time, Zscaler pulled the certificates in question from the root certificate bundles shipped with its products. The announcement thus pairs an all-clear for its own environment with a concrete technical safeguard. Both elements of the disclosure carry weight for investors: the finding from its review on one hand, the protective step on the other. The statement about absent evidence of compromise refers explicitly to Zscaler's own environment — it should not be read as a blanket clearance for every affected certificate.

Analyst Coverage Predates the Pullback

D.A. Davidson launched coverage of Zscaler with a "Neutral" rating and a $215 price target. The initiation, dated October 22 in one account and October 20 in another, predates Fortinet's quarterly report and should not be interpreted as a response to the recent sector selloff. Either way, the launch was no outright buy signal.

That rating offers an additional lens on the stock but likewise fails to explain the price move. Three separate layers therefore deserve to be kept apart: the pressured industry backdrop, Zscaler's own security disclosure, and the cautious analyst assessment. The share-price gain that accompanied the eMudhra news stands against these reservations without substituting for any new statement on operational development.

Investors weighing the stock face a similar exercise in separation. Fortinet's guidance describes Fortinet's business. The sector reaction describes sentiment. Neither amounts to evidence of a corresponding operational deterioration at Zscaler — just as the earlier positive session did not prove that the industry's worries had been laid to rest.