CVE-2021-26829

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2025-11-28. Federal remediation due 2025-12-19.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• 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

48.05% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 98.8% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

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 11:05Z5 YR AGO

Last updated

2025-12-02 04:56Z9 MO AGO

Reserved

2021-02-05

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 5.4)

CNA CVSS vector

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

Weaknesses

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base

Data version

5.2

Document digest

0d87a44e8ae660ae9b711b083f72453adbfc9ed7a06d7c54b1bd05d2e8242225

• youtu.behttps://youtu.be/Xh6LPCiLMa8x_refsource_MISC
• forum.scadabr.com.brhttp://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4x_refsource_MISC
• www.forescout.comhttps://www.forescout.com/blog/anatomy-of-a-hacktivist-attack-russian-aligned-group-targets-otics/third-party-advisory
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26829government-resource