CVE-2026-69152 juliangruber CVE debrief

Who should care

Developers and administrators using the brace-expansion library in their applications should be aware of this vulnerability and take necessary actions to mitigate it. This includes updating the library to a fixed version, implementing input validation and sanitization, and monitoring for potential denial-of-service (DoS) attacks. The vulnerability exists in the brace-expansion library, which generates arbitrary strings containing a common prefix and suffix. Prior to versions 1.1.18, 2.1.4, 3.0.6, and 5.0.9, the expand() function does not apply maxLength while constructing comma-alternative intermediate arrays or padded sequences. This allows attacker-controlled input to exhaust memory or block the event loop. The fix for CVE-2026-14257 is bypassed by this vulnerability. The CVE record was published on 2026-08-03T17:16:45.953Z and has not been modified since then. The NVD entry is currently Analyzed. The vulnerability has a HIGH CVSS severity score of 7.5 and potential for memory exhaustion or event loop blocking. High-priority defensive actions are required due to the HIGH CVSS severity score of 7.5 and potential for memory exhaustion or event loop blocking. The vulnerability exists in the brace-expansion library, which generates arbitrary strings containing a common prefix and suffix. Prior to versions 1.1.18, 2.1.4, 3.0.6, and 5.0.9, the expand() function does not apply maxLength while constructing comma-alternative intermediate arrays or padded sequences. This allows attacker-controlled input to exhaust memory or block the event loop. The fix for CVE-2026-14257 is bypassed by this vulnerability. This issue is fixed in versions 1.1.18, 2.1.4, 3.0.6, and 5.0.9. Developers and administrators using the brace-expansion library in their applications should be aware of this vulnerability and take necessary actions to mitigate it. This includes updating the library to a fixed version, implementing input validation and sanitization, and monitoring for potential denial-of-service (DoS) attacks. The vulnerability has a HIGH CVSS severity score of 7.5 and potential for memory exhaustion or event loop blocking. High-priority defensive actions are required due to the HIGH

Technical summary

The brace-expansion library generates arbitrary strings containing a common prefix and suffix. Prior to versions 1.1.18, 2.1.4, 3.0.6, and 5.0.9, the expand() function does not apply maxLength while constructing comma-alternative intermediate arrays or padded sequences. This allows attacker-controlled input to exhaust memory or block the event loop. The fix for CVE-2026-14257 is bypassed by this vulnerability. This issue is fixed in versions 1.1.18, 2.1.4, 3.0.6, and 5.0.9. Developers and administrators using the brace-expansion library in their applications should be aware of this vulnerability and take necessary actions to mitigate it.

Defensive priority

High-priority defensive actions are required due to the HIGH CVSS severity score of 7.5 and potential for memory exhaustion or event loop blocking.

Recommended defensive actions

• Update brace-expansion to version 1.1.18, 2.1.4, 3.0.6, or 5.0.9
• Implement input validation and sanitization for user-controlled input
• Monitor for potential denial-of-service (DoS) attacks
• Consider using alternative libraries or workarounds
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The vulnerability exists in the brace-expansion library, which generates arbitrary strings containing a common prefix and suffix. Prior to versions 1.1.18, 2.1.4, 3.0.6, and 5.0.9, the expand() function does not apply maxLength while constructing comma-alternative intermediate arrays or padded sequences. This allows attacker-controlled input to exhaust memory or block the event loop. The fix for CVE-2026-14257 is bypassed by this vulnerability.

Official resources