CVE-2020-26891

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

1.93% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 78.2% of scored records. A rank, not a probability.

NVD base score

6.1 (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:C/C:L/I:L/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

2020-10-19 16:47Z5 YR AGO

Last updated

2024-08-04 16:03Z2 YR AGO

Reserved

2020-10-08

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

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

Data version

5.1

Document digest

bfd7afb0e1d8cb751530d22c211761b20c86eadc3b3516dc7ebb83a2b805ceb7

• github.comhttps://github.com/matrix-org/synapse/pull/8444x_refsource_MISC
• matrix.orghttps://matrix.org/blog/2020/10/15/synapse-1-21-2-released-and-security-advisoryx_refsource_MISC
• github.comhttps://github.com/matrix-org/synapse/releases/tag/v1.21.2x_refsource_MISC
• github.comhttps://github.com/matrix-org/synapse/security/advisories/GHSA-3x8c-fmpc-5rmqx_refsource_CONFIRM