kin-openapi spec loader panics on a self-referential additionalProperties $ref (nil-pointer DoS)

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No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

kin-openapi is a Go project for handling OpenAPI files. Prior to 0.145.0, openapi3.Loader can dereference a nil SchemaRef.Value while resolving a self-referential additionalProperties JSON Reference such as a schema that points to its own additionalProperties member. Loading an attacker-controlled OpenAPI document through LoadFromData, LoadFromFile, or LoadFromURI reaches resolveComponent before document validation and can panic the loading process. Resolved additionalProperties schemas and ordinary recursive schemas do not take the vulnerable nil-value path. This issue is fixed in version 0.145.0.

Source published

15 Oct 2026 15:31:19 UTC

Source modified

15 Oct 2026 15:44:17 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

kin-openapi is a Go project for handling OpenAPI files. Prior to 0.145.0, openapi3.Loader can dereference a nil SchemaRef.Value while resolving a self-referential additionalProperties JSON Reference such as a schema that points to its own additionalProperties member. Loading an attacker-controlled OpenAPI document through LoadFromData, LoadFromFile, or LoadFromURI reaches resolveComponent before document validation and can panic the loading process. Resolved additionalProperties schemas and ordinary recursive schemas do not take the vulnerable nil-value path. This issue is fixed in version 0.145.0.

Source published

Oct 15, 2026, 3:31:19 PM (timezone not stated)

Source modified

Oct 15, 2026, 3:44:17 PM (timezone not stated)

Observed here

9 Nov 2026 04:15:07 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

kin-openapi is a Go project for handling OpenAPI files. Prior to 0.145.0, openapi3.Loader can dereference a nil SchemaRef.Value while resolving a self-referential additionalProperties JSON Reference such as a schema that points to its own additionalProperties member. Loading an attacker-controlled OpenAPI document through LoadFromData, LoadFromFile, or LoadFromURI reaches resolveComponent before document validation and can panic the loading process. Resolved additionalProperties schemas and ordinary recursive schemas do not take the vulnerable nil-value path. This issue is fixed in version 0.145.0.

Source published

15 Oct 2026 16:17:30 UTC

Source modified

15 Oct 2026 16:17:30 UTC

Observed here

25 Oct 2026 04:17:26 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

The defect ---------- Confirmed at HEAD (f0407d5, v0.144.0). openapi3/loader.go, inside resolveComponent's drill closure (around line 455), the case *SchemaRef branch for pathPart == "additionalProperties" dereferences c.Value.AdditionalProperties with no nil-check on c.Value: case *SchemaRef: if pathPart == "additionalProperties" { if ap := c.Value.AdditionalProperties.Has; ap != nil { // c.Value can be nil here cursor = *ap } else { cursor = c.Value.AdditionalProperties.Schema } attempted = true } When a $ref fragment drills through .../additionalProperties of a schema whose Value is still nil (a pure, not-yet-resolved $ref, or a self-reference resolved before its own Value is set), c.Value is nil and the .AdditionalProperties access panics. Input and attacker ------------------- A tiny crafted OpenAPI document, one schema, no external refs, no network: openapi: 3.0.3 info: {title: t, version: "1.0.0"} paths: {} components: schemas: A: $ref: '#/components/schemas/A/additionalProperties' Attacker model: any service or tool that loads an untrusted spec via the default openapi3.Loader (LoadFromData / LoadFromFile / LoadFromURI), e.g. a spec registry, an API-management platform ingesting user specs, a linter, or a converter. It crashes during LOAD (ResolveRefsIn), before Validate. Verification level ------------------ EXECUTED with negative controls (agent-run go test at HEAD f0407d5, including yesterday's security merge; the bug is still present). The full stack pins LoadFromData:196 -> ResolveRefsIn:274 -> resolveSchemaRef:1048 -> resolveComponent:485 -> drill:439 -> :455, propagating to main(); no recover() in loader.go/schema.go (grep + trace). Two negative controls stay clean: drilling additionalProperties of a resolved schema loads fine (the existing TestIssue376 happy path), and a normal recursive schema loads fine, so the nil Value is specifically the cause. I independently re-confirmed at HEAD that loader.go:455 dereferences c.Value.AdditionalProperties with no nil-check on c.Value. NOT verified: I did not enumerate every consumer's recover posture. Suggested fix ------------- Add if c.Value == nil { break } (fall through to the nil-safe drillIntoField) before touching c.Value.AdditionalProperties. One line. Also cleared (stated, not claimed) ---------------------------------- The allOf/anyOf $ref diamond does not blow up: Schema.validate threads its stack through the return and never pops it, acting as a global pointer-keyed visited-set (executed N=10..30, microseconds). External-ref SSRF/path-traversal is blocked by default (IsExternalRefsAllowed=false); the known custom-ReadFromURIFunc bypass is the already-banked downstream oasdiff item. Advisory-source note -------------------- Five-source enumeration: every kin-openapi advisory (CVE-2025-30153 plus the five fresh July-2026 GHSAs) is in openapi3filter (request validation); this finding is in the openapi3 loader, untouched by that systematic reporter and flagged un-analyzed by the prior oasdiff scout. Not contested on the loader surface as of today (a systematic hunter could pivot, so it decays; submit reasonably promptly). Dedup ----- Dedup gate clean: no kin-openapi loader verdict in COVERED-INDEX, DISCLOSURE-INDEX or SCOUT-EXCLUDE (the one DISCLOSURE-INDEX hit is report #313, the downstream oasdiff, a different repo/lane). Tooling ------- AI assistance was used while investigating. The panic is executed-verified with negative controls (a one-schema self-referential additionalProperties $ref crashes LoadFromData while a resolved additionalProperties and a normal recursive schema load fine), and I confirmed at HEAD that loader.go:455 dereferences c.Value.AdditionalProperties with no nil-check on c.Value, on a load path with no recover.

Source published

15 Oct 2026 20:15:58 UTC

Source modified

5 Nov 2026 23:26:06 UTC

Observed here

5 Nov 2026 23:38:32 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Publisher rating · MODERATE

kin-openapi spec loader panics on a self-referential additionalProperties $ref (nil-pointer DoS) in github.com/getkin/kin-openapi

Source published

5 Nov 2026 22:53:53 UTC

Source modified

5 Nov 2026 23:15:12 UTC

Observed here

5 Nov 2026 23:38:32 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.