CVE-2026-18140: Uncontrolled recursion in the unknown-key skip path of the aws-smithy-json runtime crate before 0.62.7, which

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HIGH 7.5REMOTEWATCHLISTUPGRADE

CVE-2026-18140 is a high-severity flaw (CVSS 7.5) affecting aws-smithy-json. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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-smi

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 64%)
CISA exploited list	No
Weakness	CWE-674
Published	2026-07-30
Last modified	2026-10-23

Publisher (CNA): AMZN · Vendor: amazon

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-30 19:17 UTCPublished CVE record published
2026-10-23 22:10 UTCUpdated Record last modified

amazon aws-smithy-json UPGRADE

Affected: < 0.62.7

Fixed in: 0.62.7

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy aws-smithy-json || rpm -q aws-smithy-json || aws-smithy-json --version

2. UPGRADE to 0.62.7 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade aws-smithy-json

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade aws-smithy-json

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Rust (Cargo) · aws-smithy-json · FIXED · 0.62.7 · vulnerable: <= 0.62.6 · source

Set aws-smithy-json >= 0.62.7 in Cargo.toml, then run: cargo update -p aws-smithy-json

Fedora 46 · kwin-zones · FIXED · 1.0.13-1.fc46 · FEDORA-2026-95888f332b · source

sudo dnf upgrade --advisory=FEDORA-2026-95888f332b

Fedora ELN · nginx-mod-brotli · FIXED · 1.0.0~rc-16.eln159 · FEDORA-2026-501a6a8273 · source

sudo dnf upgrade --advisory=FEDORA-2026-501a6a8273

RHEL 10 · goose · FIXED · goose-1.38.0-1.el10_2

sudo dnf upgrade --advisory=RHSA-2026:67593 rpm -q goose

RHEL 9 · goose · FIXED · goose-1.38.0-1.el9_8

sudo dnf upgrade --advisory=RHSA-2026:67595 rpm -q goose

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-18140?

aws-smithy-json: upgrade to 0.62.7. Exact commands for each OS are on this page.

Is CVE-2026-18140 being exploited?

CVE-2026-18140 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-18140 affect?

CVE-2026-18140 affects aws-smithy-json. Severity is high (CVSS 7.5). 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

How urgent is CVE-2026-18140?

Priority 45/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

AWS vulnerabilities

References

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