CVE-2021-40426

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.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total 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

2.21% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 81.0% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

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

2022-04-14 19:56Z4 YR AGO

Last updated

2025-04-15 19:07Z1 YR AGO

Reserved

2021-09-01

Assigning CNA

talos

Record state

PUBLISHED

Severity

Critical (CVSS 10.0)

CNA CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Weaknesses

• CWE-122Heap-based Buffer OverflowVariant
• CWE-787Out-of-bounds WriteBase

Data version

5.1

Document digest

0f56d576141d8bd6f847b2d4a6722674fe2a9636690bc2822cd4886372ccc157

• talosintelligence.comhttps://talosintelligence.com/vulnerability_reports/TALOS-2021-1434
• www.openwall.com[oss-security] 20230203 sox: patches for old vulnerabilitieshttp://www.openwall.com/lists/oss-security/2023/02/03/3mailing-list
• lists.debian.org[debian-lts-announce] 20230210 [SECURITY] [DLA 3315-1] sox security updatehttps://lists.debian.org/debian-lts-announce/2023/02/msg00009.htmlmailing-list
• www.debian.orgDSA-5356https://www.debian.org/security/2023/dsa-5356vendor-advisory