CVE-2026-57959: Hi.Events 1.9.0 - Promo Code Max-Usage Bypass via Asynchronous Job Race Condition

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-29 · updated 2026-10-25
Weakness: CWE-367

Description

Hi.Events through 1.9.0 contains a promo code validation vulnerability where reservation validates usage count before asynchronous UpdateEventStatisticsJob increments it, allowing attackers to redeem limited promo codes unlimited times. Attackers can sequentially reserve multiple orders with the same restricted promo code, each reading order_usage_count=0 and passing validation, then complete them all at discounted prices without concurrent requests.

Affected products

HiEventsDev Hi.Events: through 1.9.0

References

https://github.com/HiEventsDev/Hi.Events/issues/1223
https://www.vulncheck.com/advisories/hi-events-promo-code-max-usage-bypass-via-asynchronous-job-race-condition

Get alerted when CVE-2026-57959 or the next vulnerability affects your stack