Typora Mermaid Rendering cross site scripting

published 2026-08-31 2 mo ago modified 2026-08-31 2 mo ago also EUVD-2026-68614

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits: 0; none known

A vulnerability was found in Typora up to 1.13.8/1.14.6. This vulnerability affects unknown code of the component Mermaid Rendering Engine. The manipulation of the argument classDef/style results in cross site scripting. The attack may be launched remotely. The exploit has been made public and could be used. Upgrading to version 1.14.8 is able to resolve this issue. You should upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.

Patch / fix

fixed in 1 links 2

n/a Typora 1.14.8

typora.io/releases/all patch
typora.io/#download patch

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-31)

Exploit prediction

0.49% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/zzk6th/cve/issues/5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
CNA	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
CNA	3.0	4.3	CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
CNA	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:P/A:N/E:POC/RL:OF/RC:C
CNA	4.0	2.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/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	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
CNA	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

n/a Typora

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation
CWE-94 Improper Control of Generation of Code

References

typora.io /releases/all
patch
typora.io /#download
patch
github.com /zzk6th/cve/issues/5
exploit, issue-tracking
vuldb.com /vuln/397225
vdb-entry, technical-description
vuldb.com /vuln/397225/cti
signature, permissions-required
vuldb.com /cve/CVE-2026-82805
third-party-advisory
vuldb.com /submit/863528
third-party-advisory

Sources

CVE List CVE-2026-82805
NVD CVE-2026-82805

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary