CVE-2026-16756 json
Allocation of resources without limits in the default aws-smithy-http-server serve() path allows unauthenticated Slowloris denial of service
published 2026-07-23 3 mo ago modified 2026-10-24 15 d ago also GHSA-jvxp-qmx7-gjpx , EUVD-2026-48362
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 55%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.75% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 4.0 | 8.7 | 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 |
| CNA | 4.0 | 8.7 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| crates.io | aws-smithy-http-server | <0.66.5 |
0.66.5 |
Affected products
- AWS aws-smithy-http-server
Classification
- Weakness
-
- CWE-770 Allocation of Resources Without Limits or Throttling
References
-
crates.io
/crates/aws-smithy-http-server/0.66.5
release-notes, patch, web
-
aws.amazon.com
/security/security-bulletins/2026-064-aws/
vendor-advisory
-
github.com
/smithy-lang/smithy-rs/security/advisories/GHSA-jvxp-qmx7-gjpx
release-notes, web
-
nvd.nist.gov
/vuln/detail/CVE-2026-16756
advisory
-
aws.amazon.com
/security/security-bulletins/2026-064-aws
web
-
github.com
/smithy-lang/smithy-rs
package
Sources
- CVE List CVE-2026-16756
- GitHub Advisory GHSA-jvxp-qmx7-gjpx
- NVD CVE-2026-16756
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