CVE-2026-77354

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 78% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this weekElevated
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
8.7
EG Score
8.7(medium)
EG Risk
70(Attend)
EG Risk 70/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity87% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

August 21, 2026

Last Modified

August 25, 2026

Advisory Details (4)

Auto-updated Aug 21, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github, github_pr, github_commit.
github_release Patch Available

v0.142.0

Patch available: getkin/kin-openapi v0.142.0

https://github.com/getkin/kin-openapi/releases/tag/v0.142.0
github_commit Patch Available

commit 1223a0f215d2 (getkin/kin-openapi)

Patch available: getkin/kin-openapi v0.142.0 (contains commit 1223a0f215d2)

https://github.com/getkin/kin-openapi/commit/1223a0f215d2cf9beb2d9eb9ea2649d001c21388
github_pr Patch Available

openapi3filter: deepObject array of objects and array of arrays support

Patch available: getkin/kin-openapi v0.124.0 (PR #923 merged 2024-03-22)

https://github.com/getkin/kin-openapi/pull/923
github Patch Available🟡 PoC Available

Uncontrolled resource consumption in openapi3filter deepObject query parameter decoding · Advisory · getkin/kin-openapi · GitHub

https://github.com/getkin/kin-openapi/security/advisories/GHSA-xhj3-7xw9-vr34

Vendor Advisories for CVE-2026-77354(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/getkin/kin-openapi—0.142.0—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 11× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-25 20:37 UTCEG score recompute
  2. 2026-08-25 19:25 UTCEG score recompute
  3. 2026-08-25 17:09 UTCEG score recompute
  4. 2026-08-25 13:49 UTCEPSS rescore
  5. 2026-08-24 14:57 UTCEG score recompute
  6. 2026-08-24 14:18 UTCEPSS rescore
  7. 2026-08-23 12:41 UTCEG score recompute
  8. 2026-08-23 00:19 UTCEPSS rescore
  9. 2026-08-21 21:24 UTCEG score recompute
  10. 2026-08-21 20:55 UTCEG score recompute
  11. 2026-08-21 20:54 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-77354?
CVE-2026-77354 is a high vulnerability published on August 21, 2026. kin-openapi is a Go project for handling OpenAPI files. From 0.124.0 until 0.142.0, openapi3filter.sliceMapToSlice in openapi3filter/reqrespdecoder.go converts attacker-controlled sparse indexes from a deepObject query parameter into a dense slice by allocating entries from zero through the largest…
When was CVE-2026-77354 disclosed?
CVE-2026-77354 was first published in the National Vulnerability Database on August 21, 2026, with the most recent update on August 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77354 actively exploited?
CVE-2026-77354 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 77.8% of all scored CVEs.
What is the CVSS score of CVE-2026-77354?
CVE-2026-77354 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-77354?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77354, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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