CVE-2026-115845

MEDIUM 5.3

Published 2026-10-23 · Last modified 2026-10-23

An incomplete list of disallowed inputs in the Python code validator of the run_script tool in AWS MCP Server might allow an authenticated remote user to execute arbitrary code within their own isolated session environment via a crafted script. AWS fixed this issue service-side. No customer action is required.

NO EXPLOITATION SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 23rd percentile

○ In CISA KEV ○ Catalogued PoC

Impact if exploited

5.3CVSS 4.0 · MEDIUM

ConfidentialityLow
IntegrityLow
AvailabilityNone

What an attacker needs

✓Access: Reachable over the network — no local access needed
⚠Privileges: Requires a low-privilege account
✓User interaction: No user interaction needed
✓Complexity: No special conditions — reliably repeatable
✓Requirements: No special attack requirements

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

Search GitHub now — results may be empty or unverified.

Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Data snapshot: 2026-10-26T13:52:32.101Z

Affected

Vendors Aws

Products Aws Mcp Server

Weakness (CWE)

CWE-184: Incomplete list of disallowed inputs

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

References and research data (JSON)

All CVSS metrics

MEDIUM 6.4 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
MEDIUM 5.3 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
MEDIUM 5.3 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/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
MEDIUM 6.4 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

References

Advisories

https://aws.amazon.com/security/security-bulletins/2026-149-aws/ vendor-advisoryCVE record · AMZN · Updated 2026-10-23T19:04:44.790Z
NVD · CVE-2026-115845 · Updated 2026-10-23T19:23:01.467
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-109127 ADVISORYEUVD · EUVD-2026-109127

Sources: NVD · CVE.org · EPSS