CVE-2026-77354
kin-openapi: Uncontrolled resource consumption in openapi3filter deepObject query parameter decoding
Description
kin-openapi is a Go project for handling OpenAPI files. From 0.124.0 until 0.142.0, openapi3filter.sliceMapToSlice in openapi3filter/req_resp_decoder.go converts attacker-controlled sparse indexes from a deepObject query parameter into a dense slice by allocating entries from zero through the largest supplied index, after which buildResObj creates another slice of the same length. This allocation occurs before schema validation, so maxItems does not prevent it. An unauthenticated client can send a small query such as param[items][50000000]=x to an endpoint whose deepObject schema contains an array, forcing multi-gigabyte heap allocation and causing an OOM kill or restart loop. Other request-body encodings and styled parameters that do not produce bracketed integer indexes are not affected. This issue is fixed in version 0.142.0.
INFO
Published Date :
Aug. 21, 2026, 9:17 p.m.
Last Modified :
Aug. 21, 2026, 9:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-77354
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update kin-openapi to version 0.142.0.
- Apply the patch if updating is not possible.
- Validate array maxItems constraints for all inputs.
- Limit resource allocation for deepObject parameters.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-77354.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-77354 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-77354
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-77354 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-77354 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Aug. 21, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'getkin', 'product': 'kin-openapi', 'versions': [{'status': 'affected', 'version': '>= 0.124.0, < 0.142.0'}]}] Added Description kin-openapi is a Go project for handling OpenAPI files. From 0.124.0 until 0.142.0, openapi3filter.sliceMapToSlice in openapi3filter/req_resp_decoder.go converts attacker-controlled sparse indexes from a deepObject query parameter into a dense slice by allocating entries from zero through the largest supplied index, after which buildResObj creates another slice of the same length. This allocation occurs before schema validation, so maxItems does not prevent it. An unauthenticated client can send a small query such as param[items][50000000]=x to an endpoint whose deepObject schema contains an array, forcing multi-gigabyte heap allocation and causing an OOM kill or restart loop. Other request-body encodings and styled parameters that do not produce bracketed integer indexes are not affected. This issue is fixed in version 0.142.0. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-400 Added CWE CWE-789 Added Reference https://github.com/getkin/kin-openapi/commit/1223a0f215d2cf9beb2d9eb9ea2649d001c21388 Added Reference https://github.com/getkin/kin-openapi/pull/923 Added Reference https://github.com/getkin/kin-openapi/releases/tag/v0.142.0 Added Reference https://github.com/getkin/kin-openapi/security/advisories/GHSA-xhj3-7xw9-vr34