CVE catalog
CVE-2026-6658
A vulnerability in jupyter/nbconvert versions <= 7.17.0 allows for Cross-site Scripting (XSS) via unsanitized `text/vnd.mermaid` output in HTML exports. The `data_mermaid` block in `share/templates/la
- Severity
- Medium · CVSS 5.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.23% · Oct 25, 2026
A vulnerability in jupyter/nbconvert versions <= 7.17.0 allows for Cross-site Scripting (XSS) via unsanitized `text/vnd.mermaid` output in HTML exports. The `data_mermaid` block in `share/templates/lab/base.html.j2` renders `text/vnd.mermaid` cell output directly into HTML without escaping, enabling attackers to inject arbitrary HTML/JavaScript by breaking out of the `<pre>` tag. This vulnerability impacts any server using nbconvert to render notebooks as HTML, allowing attackers to execute arbitrary JavaScript in the context of users viewing the HTML export.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | nbconvert | sid | 7.17.1-2 | vulnerable |
| Debian | nbconvert | forky | 7.17.1-2 | vulnerable |
| Debian | nbconvert | trixie | 7.16.6-1+deb13u1 | vulnerable |
| Debian | nbconvert | bookworm | 6.5.3-3 | vulnerable |
| Cpe | nbconvert | Not reported | Not reported | vulnerable |
| Opensuse | python-nbconvert | tumbleweed | 7.17.1-2.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | nbconvert | source | sid | (unfixed) | not yet assigned | Not reported | Not reported |
| Debian | nbconvert | source | forky | (unfixed) | not yet assigned | Not reported | Not reported |
| Debian | nbconvert | source | trixie | (unfixed) | not yet assigned | Not reported | Not reported |
| Debian | nbconvert | source | bookworm | (unfixed) | not yet assigned | Not reported | Not reported |
| Opensuse | python-nbconvert | rpm | tumbleweed | 7.17.1-2.1 | Not reported | OPENSUSE-SU-2026:11725-1 | Not reported |
Notes
[trixie] nbconvert: Minor issue [bookworm] nbconvert: Minor issue, XSS
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [jupyter-nbconvert]Affected
Source package: [nbconvert]
Details (2)
6.5.3-3· all · bookwormAffected
nvd · nbconvert · debian · bookworm; nvd · nbconvert · debian · 12
6.5.3-3· all · bookwormAffected
nvd · nbconvert · debian · bookworm; nvd · nbconvert · debian · 12
- [python3-nbconvert]Affected
Source package: [nbconvert]
Details (2)
6.5.3-3· all · bookwormAffected
nvd · nbconvert · debian · bookworm; nvd · nbconvert · debian · 12
6.5.3-3· all · bookwormAffected
nvd · nbconvert · debian · bookworm; nvd · nbconvert · debian · 12
- [python-nbconvert-doc]Affected
Source package: [nbconvert]
Details (2)
6.5.3-3· all · bookwormAffected
nvd · nbconvert · debian · bookworm; nvd · nbconvert · debian · 12
6.5.3-3· all · bookwormAffected
nvd · nbconvert · debian · bookworm; nvd · nbconvert · debian · 12
[Debian 13 (Trixie)]
- [jupyter-nbconvert]Affected
Source package: [nbconvert]
Details (2)
7.16.6-1+deb13u1· all · trixieAffected
nvd · nbconvert · debian · 13
7.16.6-1+deb13u1· all · trixieAffected
nvd · nbconvert · debian · 13
- [python3-nbconvert]Affected
Source package: [nbconvert]
Details (2)
7.16.6-1+deb13u1· all · trixieAffected
nvd · nbconvert · debian · 13
7.16.6-1+deb13u1· all · trixieAffected
nvd · nbconvert · debian · 13
- [python-nbconvert-doc]Affected
Source package: [nbconvert]
Details (2)
7.16.6-1+deb13u1· all · trixieAffected
nvd · nbconvert · debian · 13
7.16.6-1+deb13u1· all · trixieAffected
nvd · nbconvert · debian · 13
[openSUSE Tumbleweed]
- [jupyter-nbconvert]Unknown
Source package: [python-nbconvert]
Details (1)
7.17.1-1.4· noarch · tumbleweedUnknown · Fixed:
7.17.1-2.1Version impact unknown
nvd · python-nbconvert · opensuse · tumbleweed
- [jupyter-nbconvert-latex]Unknown
Source package: [python-nbconvert]
Details (1)
7.17.1-1.4· noarch · tumbleweedUnknown · Fixed:
7.17.1-2.1Version impact unknown
nvd · python-nbconvert · opensuse · tumbleweed
- [python313-nbconvert]Unknown
Source package: [python-nbconvert]
Details (1)
7.17.1-1.4· noarch · tumbleweedUnknown · Fixed:
7.17.1-2.1Version impact unknown
nvd · python-nbconvert · opensuse · tumbleweed
- [python314-nbconvert]Unknown
Source package: [python-nbconvert]
Details (1)
7.17.1-1.4· noarch · tumbleweedUnknown · Fixed:
7.17.1-2.1Version impact unknown
nvd · python-nbconvert · opensuse · tumbleweed
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11725-1.json]
- [https://huntr.com/bounties/47570290-3b26-4477-8cfa-fdef7db5aefe]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-6658]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-6658]
- [https://osv.dev/vulnerability/openSUSE-SU-2026:11725-1]
- [https://security-tracker.debian.org/tracker/CVE-2026-6658]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6658.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]