Cloudflare discloses 155 AI data leaks while Cloudflare stock costs EUR 275.10

Published on 10/29/2026 at 12:10 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS

Cloudflare says 155 responses exposed customer data from August 27 to September 9, 2026. Cloudflare stock costs EUR 275.10 on October 29, 2026.

Security disclosure and remediation

Cloudflare disclosed 155 affected GLM-5.3 responses on October 26, 2026.
The company expanded the cache pool to 2.04 million tokens and applied engine fixes before restoring service.
Cloudflare stock traded at EUR 275.10 at 12:05 p.m. CET at Lang & Schwarz on October 29, 2026.

NET, US18915M1071, Illustration mit AI erstellt.

Cloudflare (ISIN US18915M1071) disclosed that 155 responses from its GLM-5.3 Workers AI model contained data from other customers' requests between August 27 and September 9, 2026. The company published the incident report on October 26, 2026, and said the model was restored after configuration and engine fixes.

The report from Cloudflare says every affected response followed a prompt longer than 681,280 tokens. The model had been configured with a 1,048,576-token context window, while the prefill key-value cache pool could hold only 681,280 tokens.

How the exposure occurred

A configuration mismatch combined with a rejection-handling bug in SGLang, the open-source inference engine used by Cloudflare. Rejected long prompts moved through the disaggregated prefill and decode process, allowing the decode stage to read stale cache pages from earlier requests.

Cloudflare took GLM-5.3 offline after reproducing the issue and restored it on September 9, 2026. The company expanded the prefill cache pool to about 2.04 million tokens, added checks comparing cache capacity with context length and applied an engine patch before returning the model to public access.

What the disclosure means

Cloudflare identified GLM-5.3 as the only affected Workers AI model in the incident. The company also said the identified requests matched ordinary long-context use and described the disclosure as coordinated with the SGLang maintainers.

The report recommends that operators running SGLang in disaggregated prefill and decode mode compare cache capacity with context length and upgrade to version 0.5.22 or later. That guidance broadens the relevance beyond Cloudflare because the underlying engine is open source.

Stock context on October 29

Cloudflare stock was trading at EUR 275.10 at Lang & Schwarz on October 29, 2026 at 12:05 p.m. CET. The primary exchange is the New York Stock Exchange, where Cloudflare trades under the ticker NET; the finance quote showed a USD 113.5 billion market capitalization based on the October 28, 2026 quote.

The further course of trading is shown by the continuously updated real-time quote of Cloudflare stock.