CVE-2021-26828

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2025-12-03. Federal remediation due 2025-12-24.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• 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

39.36% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 98.5% 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:L/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

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

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

2021-06-11 11:10Z5 YR AGO

Last updated

2025-12-04 04:55Z9 MO AGO

Reserved

2021-02-05

Assigning CNA

mitre

Record state

PUBLISHED

Severity

High (CVSS 8.8)

CNA CVSS vector

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

Weaknesses

• CWE-434Unrestricted Upload of File with Dangerous TypeBase

Data version

5.2

Document digest

fc5904e47c6f4692abba2c4d8bdb39948349f15599c942dc28f881dfd3c4bcaa

• youtu.behttps://youtu.be/k1teIStQr1Ax_refsource_MISC
• packetstormsecurity.comhttp://packetstormsecurity.com/files/162564/ScadaBR-1.0-1.1CE-Linux-Shell-Upload.htmlx_refsource_MISC
• forum.scadabr.com.brhttp://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4x_refsource_MISC
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26828government-resource
• github.comhttps://github.com/SCADA-LTS/Scada-LTS/pull/2174issue-tracking