CVE-2026-59710

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• 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

0.34% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 26.2% 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

Deferred. NVD last modified this record on 2026-07-07.

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

2026-07-06 21:15Z1 MO AGO

Last updated

2026-07-07 13:47Z1 MO AGO

Reserved

2026-07-06

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

4c2195f3003978818d02933af3f6f95a5fffe1e59c543b1e5ed9dffaadb6403e

• github.comGitHub Issuehttps://github.com/showdownjs/showdown/issues/1046issue-tracking
• github.comProducthttps://github.com/showdownjs/showdownproduct
• github.comhttps://github.com/showdownjs/showdown/commit/e5cab1e9a5dcea2bb3cbf888863fa7e65ab37edfpatch
• www.vulncheck.comhttps://www.vulncheck.com/advisories/showdown-stored-xss-via-unescaped-table-header-id-attribute-injectionthird-party-advisory