Description
An XSS vulnerability was discovered in noVNC before 0.6.2 in which the remote VNC server could inject arbitrary HTML into the noVNC web page via the messages propagated to the status field, such as the VNC server name.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | novnc | 1:1.0.0-1 | — |
| Debian 13 | novnc | 1:1.0.0-1 | — |
| Debian 12 | novnc | 1:1.0.0-1 | — |
| Debian 9 | novnc | 1:0.4+dfsg+1+20131010+gitf68af8af3d-6+deb9u1 | DLA-2854-1 |
| Debian 8 | novnc | 1:0.4+dfsg+1+20131010+gitf68af8af3d-4+deb8u1 | DLA-1946-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | novnc | No fix yet | — |
| Ubuntu 16.04 LTS | novnc | 1:0.4+dfsg+1+20131010+gitf68af8af3d-4+deb8u1build0.16.04.1 | USN-4522-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Rhev Manager 4 | novnc | 1.1.0-1.el8ost | RHSA-2020:3247 |
| Red Hat Rhev Manager 4 | ovirt-engine-api-explorer | 0.0.6-1.el8ev | RHSA-2020:3247 |
| Red Hat Rhev Manager 4 | ovirt-engine-ui-extensions | 1.2.2-1.el8ev | RHSA-2020:3247 |
| Red Hat Rhev Manager 4 | rhvm +19 | 4.4.1.8-0.7.el8ev | RHSA-2020:3247 |
| Red Hat Rhev Manager 4 | rhvm-dependencies | 4.4.0-1.el8ev | RHSA-2020:3247 |
| Red Hat OpenStack 13 | novnc | 1.1.0-2.el7ost | RHSA-2020:0754 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
ShielderSec/CVE-2017-18635 ★ 5 · Oct 16, 2019
PoC for CVE-2017-18635
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| npm | @novnc/novnc | < 0.6.2 | 0.6.2 | GHSA-49rv-g7w5-m8xx |
Advisories 5
- RHSA-2020:3247 Red Hat Security Advisory: RHV Manager (ovirt-engine) 4.4 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 9, 2026
- RHSA-2020:0754 Red Hat Security Advisory: novnc security update Red Hat Security Advisories (RHSA) · Oct 8, 2026
- USN-4522-1 novnc vulnerability Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-1946-1 novnc - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2854-1 novnc - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- https://github.com/novnc/noVNC/issues/748
- https://github.com/novnc/noVNC/releases/tag/v0.6.2
- https://bugs.launchpad.net/horizon/+bug/1656435
- https://github.com/novnc/noVNC/commit/6048299a138e078aed210f163111698c8c526a13#diff-286f7dc7b881e942e97cd50c10898f03L534
- [debian-lts-announce] 20191005 [SECURITY] [DLA 1946-1] novnc security update mailing-list
- https://www.shielder.it/blog/exploiting-an-old-novnc-xss-cve-2017-18635-in-openstack/
- https://github.com/ShielderSec/cve-2017-18635
- RHSA-2020:0754 vendor-advisory
- USN-4522-1 vendor-advisory
- [debian-lts-announce] 20211228 [SECURITY] [DLA 2854-1] novnc security update mailing-list