CVE-2026-18140

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 63% 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
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

Uncontrolled recursion in the unknown-key skip path of the aws-smithy-json runtime crate before 0.62.7, which the smithy-rs code generator invokes from every generated struct deserializer, might allow remote unauthenticated users to cause a denial of service (process abort via stack exhaustion) via a single small HTTP request containing deeply nested JSON to a smithy-rs generated server.

To remediate this issue, users should upgrade to aws-smithy-json 0.62.7 or later and rebuild.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
38(Track)
EG Risk 38/100SSVC: Track

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
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

July 30, 2026

Last Modified

August 10, 2026

Advisory Details (3)

Auto-updated Jul 30, 2026
Patch available. Sources: github.
github Patch Available

Uncontrolled recursion in the aws-smithy-json unknown-key skip path allows unauthenticated remote denial of service in smithy-rs generated servers · Advisory · smithy-lang/smithy-rs · GitHub

https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-8ffr-xgwf-xj56
generic

crates.io: Rust Package Registry

https://crates.io/crates/aws-smithy-json/0.62.7

Vendor Advisories for CVE-2026-18140(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 41× 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. 2026-08-19 19:28 UTCEG score recompute
  2. 2026-08-19 17:03 UTCEPSS rescore
  3. 2026-08-18 19:39 UTCEG score recompute
  4. 2026-08-18 13:48 UTCEPSS rescore
  5. 2026-08-17 19:43 UTCEG score recompute
  6. 2026-08-17 13:47 UTCEPSS rescore
  7. 2026-08-16 18:50 UTCEG score recompute
  8. 2026-08-16 14:56 UTCEPSS rescore
  9. 2026-08-16 06:46 UTCEG score recompute
  10. 2026-08-16 02:14 UTCEPSS rescore
  11. 2026-08-15 07:02 UTCEG score recompute
  12. 2026-08-15 01:30 UTCEPSS rescore
  13. 2026-08-14 07:17 UTCEG score recompute
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-12 19:37 UTCEG score recompute
  16. 2026-08-12 13:50 UTCEPSS rescore
  17. 2026-08-11 19:52 UTCEG score recompute
  18. 2026-08-11 13:42 UTCEPSS rescore
  19. 2026-08-11 08:00 UTCEG score recompute
  20. 2026-08-11 00:00 UTCEPSS rescore
  21. 2026-08-09 18:07 UTCEG score recompute
  22. 2026-08-09 13:46 UTCEPSS rescore
  23. 2026-08-08 18:23 UTCEG score recompute
  24. 2026-08-08 16:37 UTCEPSS rescore
  25. 2026-08-07 18:38 UTCEG score recompute
Show 16 more
  1. 2026-08-06 18:54 UTCEG score recompute
  2. 2026-08-06 13:46 UTCEPSS rescore
  3. 2026-08-06 07:02 UTCEG score recompute
  4. 2026-08-05 19:17 UTCEPSS rescore
  5. 2026-08-04 19:26 UTCEG score recompute
  6. 2026-08-04 15:10 UTCEPSS rescore
  7. 2026-08-04 10:38 UTCEPSS rescore
  8. 2026-08-03 19:37 UTCEG score recompute
  9. 2026-08-03 10:35 UTCEPSS rescore
  10. 2026-08-02 08:01 UTCEG score recompute
  11. 2026-08-02 02:26 UTCEPSS rescore
  12. 2026-08-01 08:16 UTCEG score recompute
  13. 2026-08-01 04:15 UTCEPSS rescore
  14. 2026-07-30 19:30 UTCEG score recompute
  15. 2026-07-30 18:56 UTCEG score recompute
  16. 2026-07-30 18:55 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-18140?
CVE-2026-18140 is a high vulnerability published on July 30, 2026. Uncontrolled recursion in the unknown-key skip path of the aws-smithy-json runtime crate before 0.62.7, which the smithy-rs code generator invokes from every generated struct deserializer, might allow remote unauthenticated users to cause a denial of service (process abort via stack exhaustion) via…
When was CVE-2026-18140 disclosed?
CVE-2026-18140 was first published in the National Vulnerability Database on July 30, 2026, with the most recent update on August 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18140 actively exploited?
CVE-2026-18140 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 63.5% of all scored CVEs.
What is the CVSS score of CVE-2026-18140?
CVE-2026-18140 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-18140?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18140, 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

Explore the affected products and dependency analysis for CVE-2026-18140

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