Vulnerability · Published Aug 21, 2026 · Assigned by GitHub_M
CVE-2026-77354kin-openapi: Uncontrolled resource consumption in openapi3filter deepObject query parameter decoding
High 8.7
In plain English
A high-severity uncontrolled resource consumption in kin-openapi from getkin. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | golang-github-getkin-kin-openapi | no fix listed | DEBIAN-CVE-2026-77354 |
| Debian:13 | golang-github-getkin-kin-openapi | no fix listed | DEBIAN-CVE-2026-77354 |
| Debian:14 | golang-github-getkin-kin-openapi | no fix listed | DEBIAN-CVE-2026-77354 |
| Go | github.com/getkin/kin-openapi | 0.142.0 | GHSA-xhj3-7xw9-vr34 |
| Go | github.com/getkin/kin-openapi | 0.142.0 | GO-2026-6275 |
| Ubuntu:22.04:LTS | golang-github-getkin-kin-openapi | no fix listed | UBUNTU-CVE-2026-77354 |
| Ubuntu:24.04:LTS | golang-github-getkin-kin-openapi | no fix listed | UBUNTU-CVE-2026-77354 |
| Ubuntu:26.04:LTS | golang-github-getkin-kin-openapi | no fix listed | UBUNTU-CVE-2026-77354 |
| Ubuntu:26.10 | golang-github-getkin-kin-openapi | no fix listed | UBUNTU-CVE-2026-77354 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| getkin | kin-openapi | >= 0.124.0, < 0.142.0 |
Weakness: CWE-400, CWE-789 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/getkin/kin-openapi/security/advisories/GHSA-xhj3-7xw9-vr34 x_refsource_CONFIRM
- https://github.com/getkin/kin-openapi/pull/923 x_refsource_MISC
- https://github.com/getkin/kin-openapi/commit/1223a0f215d2cf9beb2d9eb9ea2649d001c21388 x_refsource_MISC
- https://github.com/getkin/kin-openapi/releases/tag/v0.142.0 x_refsource_MISC