CVE-2026-72912Public exploitNetwork attack vectorHinoki check available

Browser-tab freeze via pretty-recipe regex backtracking

Published Aug 10, 2026 · Updated Aug 10, 2026

Client-side ReDoS in GCHQ CyberChef before 11.3.0 allows remote attackers to freeze a browser tab through a crafted recipe URL. Utils.parseRecipeConfig() synchronously applies a complex global regular expression to a malformed #recipe= fragment with many unmatched quotes, causing heavy backtracking before rejection. A victim must open the link; the resulting startup stall lasts seconds or longer and affects availability without code execution, data disclosure, or privilege escalation.

CVSS severity4.3
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Client-side ReDoS in GCHQ CyberChef before 11.3.0 allows remote attackers to freeze a browser tab through a crafted recipe URL. Utils.parseRecipeConfig() synchronously applies a complex global regular expression to a malformed #recipe= fragment with many unmatched quotes, causing heavy backtracking before rejection. A victim must open the link; the resulting startup stall lasts seconds or longer and affects availability without code execution, data disclosure, or privilege escalation.

The record

CVE
CVE-2026-72912
Published
Aug 10, 2026
Updated
Aug 10, 2026
Vendor
GCHQ
Product
CyberChef
Classifications
CWE-400, CWE-1333, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 11.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GCHQ · CyberChefversion=< 11.3.0

Published CVSS scores

4.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-1333Inefficient Regular Expression Complexity
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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