CVE-2026-9539

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• 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

0.22% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 12.5% of scored records. A rank, not a probability.

NVD base score

6.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

NVD analysis status

Awaiting Analysis. NVD last modified this record on 2026-10-25.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

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

2026-06-24 04:37Z4 MO AGO

Last updated

2026-06-24 12:39Z4 MO AGO

Reserved

2026-05-26

Assigning CNA

STAR_Labs

Record state

PUBLISHED

Severity

Medium (CVSS 6.5)

CNA CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Weaknesses

• CWE-125Out-of-bounds ReadBase

Data version

5.2

Document digest

5f653771f1a1b27738d749676193aea50f2703ea9f77bcb482ccbb468eded4ff

• gitlab.freedesktop.orghttps://gitlab.freedesktop.org/slirp/libslirp/-/work_items/93issue-tracking
• gitlab.freedesktop.orghttps://gitlab.freedesktop.org/slirp/libslirp/-/commit/927bca7344e31fd58e2f7afaca784aad4400eb84patch
• gitlab.freedesktop.orghttps://gitlab.freedesktop.org/slirp/libslirp/-/releases/v4.9.2release-notes