CVE-2021-21265

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

1.75% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 75.8% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

NVD analysis status

Modified. 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

2021-03-10 21:15Z5 YR AGO

Last updated

2025-05-29 23:27Z1 YR AGO

Reserved

2020-12-22

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Medium (CVSS 6.8)

CNA CVSS vector

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

Weaknesses

• CWE-644Improper Neutralization of HTTP Headers for Scripting SyntaxVariant

Data version

5.1

Document digest

f932c5313e7821b6c9a0b195aa305a2b33982d7b19a55af010824b42b7a48d8a

• github.comhttps://github.com/octobercms/october/security/advisories/GHSA-xhfx-hgmf-v6vpx_refsource_CONFIRM
• github.comhttps://github.com/octobercms/library/commit/f29865ae3db7a03be7c49294cd93980ec457f10dx_refsource_MISC
• github.comhttps://github.com/octobercms/library/commit/f86fcbcd066d6f8b939e8fe897409d152b11c3c6x_refsource_MISC
• github.comhttps://github.com/octobercms/october/commit/555ab61f2313f45d7d5d138656420ead536c5d30x_refsource_MISC
• github.comhttps://github.com/octobercms/october/commit/f638d3f78cfe91d7f6658820f9d5e424306a3db0x_refsource_MISC
• packagist.orghttps://packagist.org/packages/october/backendx_refsource_MISC