CVE-2026-77354: CWE-400: Uncontrolled Resource Consumption in getkin kin-openapi
Description
CVE-2026-77354 is a high-severity uncontrolled resource consumption vulnerability in the kin-openapi Go project affecting versions from 0.124.0 up to but not including 0.142.0. The vulnerability arises from the openapi3filter.sliceMapToSlice function, which converts attacker-controlled sparse indexes from a deepObject query parameter into a dense slice, causing large memory allocations before schema validation. An unauthenticated attacker can exploit this by sending a crafted query parameter with a large index, leading to multi-gigabyte heap allocations that can cause out-of-memory (OOM) kills or restart loops. The issue is fixed in version 0.142.0.
CVSS v4.0
Score 8.7high
Affected software
getkin
kin-openapi
pkg:golang/github.com/getkin/kin-openapiRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
In kin-openapi versions >=0.124.0 and <0.142.0, the openapi3filter.sliceMapToSlice function in openapi3filter/req_resp_decoder.go improperly handles sparse indexes from deepObject query parameters by allocating a dense slice from zero to the largest index before schema validation. This allows an unauthenticated attacker to trigger excessive memory allocation by sending a query such as param[items][50000000]=x, causing multi-gigabyte heap usage and potential service disruption due to OOM kills or restart loops. The vulnerability does not affect other request-body encodings or styled parameters that do not produce bracketed integer indexes. The issue is resolved in version 0.142.0.
Potential Impact
An unauthenticated attacker can cause a denial of service by triggering excessive memory allocation through crafted deepObject query parameters, leading to out-of-memory conditions and potential service crashes or restart loops. This impacts availability of services using affected kin-openapi versions.
Mitigation Recommendations
Upgrade kin-openapi to version 0.142.0 or later where this vulnerability is fixed. No other mitigations are indicated. Patch status is confirmed by the vendor advisory stating the fix is in 0.142.0.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-08-20T19:28:35.244Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a88be20acd9273b49bcc7b5
Added to database: 08/21/2026, 21:07:44 UTC
Last enriched: 09/10/2026, 15:49:06 UTC
Last updated: 10/05/2026, 18:48:22 UTC
Views: 93
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