cti-transmute Conversion Table Allows XSS via Unescaped Cell Content During Search Highlighting

published 2026-08-11 2 mo ago modified 2026-10-24 15 d ago also EUVD-2026-55993

cvss: 5.1; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits: 0; none known

Affected versions of cti-transmute improperly handle conversion-table values passed through the search highlighting feature. The highlight() function previously returned the underlying text directly when no search query was supplied, or performed a regex replacement that inserted <mark> tags without first escaping the original content. Because the resulting value is used by an HTML-rendering sink, malicious markup contained in conversion data could be interpreted as HTML rather than displayed as text.

The fix introduces a shared highlightMatches() helper that first converts special characters such as <, >, &, and quotes into HTML entities. Only after escaping does the code insert the application-controlled <mark> element used for search highlighting.

Patch / fix

links 1

github.com/MISP/cti-transmute@ac49564 commit

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-11)

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CNA	4.0	5.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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

Affected products

MISP cti-transmute

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation
CWE-116 Improper Encoding or Escaping of Output

References

github.com /MISP/cti-transmute/commit/ac495641ef3ca927676a73ba8f1bcdfd952413df
patch

Sources

CVE List CVE-2026-73161
NVD CVE-2026-73161

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