CVE-2026-5857

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.54% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 43.1% of scored records. A rank, not a probability.

NVD base score

9.2 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/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

NVD analysis status

Received. NVD last modified this record on 2026-08-13.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-08-06 18:52Z29 DAYS AGO

Last updated

2026-08-14 16:50Z21 DAYS AGO

Reserved

2026-04-08

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

Critical (CVSS 9.2)

CNA CVSS vector

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

Weaknesses

• CWE-787Out-of-bounds WriteBase

Data version

5.2

Document digest

ffaf74db5d4c5b985d5306e90d2077364bdebfb4f82e704d4194b8bdc314a4a4

• github.comhttps://github.com/contiki-ng/contiki-ngproduct
• github.comhttps://github.com/contiki-ng/contiki-ng/pull/3163issue-tracking
• github.comhttps://github.com/contiki-ng/contiki-ng/commit/a34a2dbdc8bea784bd2ae5079aa4be520cd74f2dpatch
• y637f9qq2x.comBlog Posthttps://y637f9qq2x.com/posts/cve-2026-5857/technical-description