Vulnerability details

CVE-2026-5747

AWS Firecracker

Out-of-bounds Write in Firecracker virtio-pci Transport

CVSS 4.0

8.7High

Official description

An out-of-bounds write issue in the virtio PCI transport in Firecracker 1.13.0 through 1.14.3 and 1.15.0 on x86_64 and aarch64 might allow a local guest user with root privileges to crash the Firecracker VMM process or potentially execute arbitrary code on the host via modification of virtio queue configuration registers after device activation. Achieving code execution on the host requires additional preconditions, such as the use of a custom guest kernel or specific snapshot configurations. To remediate this, users should upgrade to Firecracker 1.14.4 or 1.15.1 and later.

CVSS scores

Score	Version	Source	Vector
8.7High	4.0	CVEProject cvelistV5 (CNA) (AMZN)	`CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`
7.5High	3.1	CVEProject cvelistV5 (CNA) (AMZN)	`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H`

Affected products

Vendor	Product	Versions	Source
AWS	Firecracker	1.15.0	CVEProject cvelistV5 (CNA)
AWS	Firecracker	1.13.0 ≤ v ≤ 1.14.3	CVEProject cvelistV5 (CNA)

References and advisories

https://github.com/firecracker-microvm/firecracker/releases/tag/v1.15.1 patch
https://github.com/firecracker-microvm/firecracker/releases/tag/v1.14.4 patch
https://aws.amazon.com/security/security-bulletins/2026-015-aws/ vendor-advisory
https://github.com/firecracker-microvm/firecracker/security/advisories/GHSA-776c-mpj7-jm3r third-party-advisory

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Details

Published: 2026-04-08
Last updated: 2026-04-20
State: Published
Assigner (CNA): AMZN

Exploit prediction (EPSS)

0.26%

Probability of exploitation in 30 days

18.8%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: No
Exploitation: None
Technical impact: Total

Weaknesses (CWE)

CWE-787
Out-of-bounds write
CWE-369
Divide by zero