CVE-2026-104477

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• 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

0.18% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 8.2% of scored records. A rank, not a probability.

NVD base score

5.3 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Awaiting Analysis. NVD last modified this record on 2026-10-06.

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

2026-10-02 23:28Z26 DAYS AGO

Last updated

2026-10-05 20:30Z23 DAYS AGO

Reserved

2026-10-02

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

Medium (CVSS 5.3)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

Weaknesses

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

Data version

5.2

Document digest

b85e5b4aee574d1489da66c96492949c33c8b69b3c44fed1f494b2ca87faa5c9

• github.comPatch Commithttps://github.com/showdownjs/showdown/commit/4fb992cd26631c108ec0410342630c80207ec7c6patch
• github.comhttps://github.com/showdownjs/showdownproduct
• www.vulncheck.comVulnCheck Advisory: Showdown through 2.1.0 XSS via unescaped quote in href and src attributeshttps://www.vulncheck.com/advisories/showdown-through-2.1.0-xss-via-unescaped-quote-in-href-and-src-attributesthird-party-advisory