CVE-2026-16756

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: 0.8%, top 47% 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: 1%CVSS: 7.5Exploit: None knownExposed: 0

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

Missing connection and header-read timeouts and the absence of a concurrent-connection cap in the default serve() path of Amazon aws-smithy-http-server might allow remote attackers to cause a denial of service by opening many connections and sending partial requests that are never completed, exhausting server sockets and tasks.

To mitigate this issue, users should upgrade to aws-smithy-http-server 0.66.5 or later.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
53%
KEV
Not listed

Published

July 23, 2026

Last Modified

August 12, 2026

Advisory Details (3)

Auto-updated Jul 23, 2026
Patch available. Sources: github.
github Patch Available

Allocation of resources without limits in the default aws-smithy-http-server serve() path allows unauthenticated Slowloris denial of service · Advisory · smithy-lang/smithy-rs · GitHub

https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-jvxp-qmx7-gjpx
generic

CVE-2026-16756 - Allocation of resources without limits in the default aws-smithy-http-server serve() path allows unauthenticated Slowloris denial of service

https://aws.amazon.com/security/security-bulletins/2026-064-aws/
generic

crates.io: Rust Package Registry

https://crates.io/crates/aws-smithy-http-server/0.66.5

Affected Packages

(1 across 1 ecosystem)
crates.io(1)
PackageVulnerable rangeFixed inDependents
aws-smithy-http-server0.66.5

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 47× 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. 2026-09-14 03:29 UTCEG score recompute
  2. 2026-09-13 16:46 UTCEPSS rescore
  3. 2026-09-12 16:44 UTCEG score recompute
  4. 2026-09-12 15:00 UTCEPSS rescore
  5. 2026-09-11 16:42 UTCEG score recompute
  6. 2026-09-11 14:52 UTCEPSS rescore
  7. 2026-09-11 09:36 UTCEPSS rescore
  8. 2026-09-10 15:08 UTCEG score recompute
  9. 2026-09-10 09:34 UTCEPSS rescore
  10. 2026-09-09 08:54 UTCEG score recompute
  11. 2026-09-08 22:00 UTCEPSS rescore
  12. 2026-09-07 21:29 UTCEG score recompute
  13. 2026-09-07 16:01 UTCEPSS rescore
  14. 2026-09-06 13:47 UTCEPSS rescore
  15. 2026-09-05 19:27 UTCEG score recompute
  16. 2026-09-05 06:58 UTCEG score recompute
  17. 2026-09-04 13:15 UTCEG score recompute
  18. 2026-09-04 05:06 UTCEPSS rescore
  19. 2026-09-02 14:11 UTCEPSS rescore
  20. 2026-09-01 23:21 UTCEG score recompute
  21. 2026-09-01 13:53 UTCEPSS rescore
  22. 2026-09-01 04:39 UTCEPSS rescore
  23. 2026-08-30 23:46 UTCEG score recompute
  24. 2026-08-30 19:17 UTCEPSS rescore
  25. 2026-08-30 12:11 UTCEG score recompute
Show 71 more
  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-30 00:30 UTCEG score recompute
  3. 2026-08-28 21:41 UTCEPSS rescore
  4. 2026-08-27 21:44 UTCEG score recompute
  5. 2026-08-27 14:25 UTCEPSS rescore
  6. 2026-08-26 19:54 UTCEG score recompute
  7. 2026-08-26 14:46 UTCEPSS rescore
  8. 2026-08-25 17:45 UTCEG score recompute
  9. 2026-08-25 13:48 UTCEPSS rescore
  10. 2026-08-24 18:08 UTCEG score recompute
  11. 2026-08-23 05:36 UTCEG score recompute
  12. 2026-08-23 00:19 UTCEPSS rescore
  13. 2026-08-22 06:26 UTCEG score recompute
  14. 2026-08-21 23:49 UTCEPSS rescore
  15. 2026-08-21 07:16 UTCEG score recompute
  16. 2026-08-20 22:55 UTCEPSS rescore
  17. 2026-08-19 20:31 UTCEG score recompute
  18. 2026-08-19 17:03 UTCEPSS rescore
  19. 2026-08-18 18:58 UTCEG score recompute
  20. 2026-08-18 13:48 UTCEPSS rescore
  21. 2026-08-17 17:24 UTCEG score recompute
  22. 2026-08-17 13:47 UTCEPSS rescore
  23. 2026-08-16 17:50 UTCEG score recompute
  24. 2026-08-16 14:56 UTCEPSS rescore
  25. 2026-08-16 06:14 UTCEG score recompute
  26. 2026-08-16 02:14 UTCEPSS rescore
  27. 2026-08-15 07:05 UTCEG score recompute
  28. 2026-08-15 01:30 UTCEPSS rescore
  29. 2026-08-14 07:06 UTCEG score recompute
  30. 2026-08-13 22:00 UTCEPSS rescore
  31. 2026-08-12 20:21 UTCEG score recompute
  32. 2026-08-12 19:22 UTCEG score recompute
  33. 2026-08-12 13:50 UTCEPSS rescore
  34. 2026-08-11 14:18 UTCEG score recompute
  35. 2026-08-11 13:42 UTCEPSS rescore
  36. 2026-08-11 02:44 UTCEG score recompute
  37. 2026-08-11 00:00 UTCEPSS rescore
  38. 2026-08-09 15:59 UTCEG score recompute
  39. 2026-08-09 13:46 UTCEPSS rescore
  40. 2026-08-08 16:50 UTCEG score recompute
  41. 2026-08-08 16:37 UTCEPSS rescore
  42. 2026-08-07 17:40 UTCEG score recompute
  43. 2026-08-06 18:29 UTCEG score recompute
  44. 2026-08-06 13:46 UTCEPSS rescore
  45. 2026-08-05 19:19 UTCEG score recompute
  46. 2026-08-05 19:17 UTCEPSS rescore
  47. 2026-08-04 20:10 UTCEG score recompute
  48. 2026-08-04 15:10 UTCEPSS rescore
  49. 2026-08-04 10:38 UTCEPSS rescore
  50. 2026-08-03 21:00 UTCEG score recompute
  51. 2026-08-03 10:35 UTCEPSS rescore
  52. 2026-08-02 10:12 UTCEG score recompute
  53. 2026-08-02 02:26 UTCEPSS rescore
  54. 2026-08-01 11:02 UTCEG score recompute
  55. 2026-08-01 04:15 UTCEPSS rescore
  56. 2026-07-31 00:16 UTCEG score recompute
  57. 2026-07-30 12:41 UTCEG score recompute
  58. 2026-07-30 01:30 UTCEPSS rescore
  59. 2026-07-29 01:54 UTCEG score recompute
  60. 2026-07-27 15:05 UTCEG score recompute
  61. 2026-07-27 14:13 UTCEPSS rescore
  62. 2026-07-27 02:19 UTCEG score recompute
  63. 2026-07-26 14:54 UTCEPSS rescore
  64. 2026-07-26 14:54 UTCEPSS rescore
  65. 2026-07-26 14:42 UTCEG score recompute
  66. 2026-07-26 03:07 UTCEG score recompute
  67. 2026-07-25 14:17 UTCEPSS rescore
  68. 2026-07-25 14:17 UTCEPSS rescore
  69. 2026-07-24 14:17 UTCEPSS rescore
  70. 2026-07-23 18:52 UTCEG score recompute
  71. 2026-07-23 18:51 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-16756?
CVE-2026-16756 is a high vulnerability published on July 23, 2026. Missing connection and header-read timeouts and the absence of a concurrent-connection cap in the default serve() path of Amazon aws-smithy-http-server might allow remote attackers to cause a denial of service by opening many connections and sending partial requests that are never completed,…
When was CVE-2026-16756 disclosed?
CVE-2026-16756 was first published in the National Vulnerability Database on July 23, 2026, with the most recent update on August 12, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16756 actively exploited?
CVE-2026-16756 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 47.0% of all scored CVEs.
What is the CVSS score of CVE-2026-16756?
CVE-2026-16756 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-16756?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-16756, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-16756

Explore →

Is Your Infrastructure Affected by CVE-2026-16756?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.