Description
An issue was discovered in LibVNCServer before 0.9.13. Byte-aligned data is accessed through uint32_t pointers in libvncclient/rfbproto.c. NOTE: there is reportedly "no trust boundary crossed.
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 | libvncserver | 0.9.13+dfsg-1 | — |
| Debian 13 | libvncserver | 0.9.13+dfsg-1 | — |
| Debian 12 | libvncserver | 0.9.13+dfsg-1 | — |
| Debian 9 | libvncserver | 0.9.11+dfsg-1.3~deb9u5 | DLA-2347-1 |
| Debian 8 | libvncserver | 0.9.9+dfsg2-6.1+deb8u8 | DLA-2264-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | libvncserver | 0.9.12+dfsg-9ubuntu0.2 | USN-4434-1 |
| Ubuntu 18.04 LTS | libvncserver | 0.9.11+dfsg-1ubuntu1.3 | USN-4434-1 |
| Ubuntu 16.04 LTS | libvncserver | 0.9.10+dfsg-3ubuntu0.16.04.5 | USN-4434-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | LibVNCServer | 0.9.10-4.22.1 | SUSE-SU-2020:1922-1 |
| SLES 15 SP1 | LibVNCServer | 0.9.10-4.22.1 | SUSE-SU-2020:1922-1 |
| SLES 12 SP5 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SLES 12 SP4 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SLES 12 SP3 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SLES 11 SP4 | LibVNCServer | 0.9.1-160.19.1 | SUSE-SU-2020:14424-1 |
| SLES for SAP 12 SP5 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SLES for SAP 12 SP4 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SLES for SAP 12 SP3 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SLES for SAP 12 SP2 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SUSE OpenStack Cloud Crowbar 9 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SUSE OpenStack Cloud Crowbar 8 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SUSE OpenStack Cloud 9 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SUSE OpenStack Cloud 8 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SUSE OpenStack Cloud 7 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | LibVNCServer | 0.9.1-160.19.1 | SUSE-SU-2020:14424-1 |
| SUSE HPE Helion OpenStack 8 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
| SUSE Enterprise Storage 5 | LibVNCServer | 0.9.9-17.31.1 | SUSE-SU-2020:2167-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.2 | LibVNCServer | 0.9.10-lp152.9.4.2 | openSUSE-SU-2020:1056-1, openSUSE-SU-2020:1025-1 |
| openSUSE Leap 15.1 | LibVNCServer | 0.9.10-lp151.7.9.1 | openSUSE-SU-2020:0988-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.23 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.22 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.21 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.20 | libvncserver | 0.9.13-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.18 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.17 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.16 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.15 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.14 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.13 | libvncserver | 0.9.13-r0 | — |
| Alpine v3.12 | libvncserver | 0.9.13-r0 | — |
Advisories 9
- USN-4434-1 libvncserver vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-2347-1 libvncserver - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2264-1 libvncserver - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2020:0988-1 Security update for LibVNCServer SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:14424-1 Security update for LibVNCServer SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2167-1 Security update for LibVNCServer SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1025-1 Security update for LibVNCServer SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1922-1 Security update for LibVNCServer SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1056-1 Security update for LibVNCServer SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13
- https://github.com/LibVNC/libvncserver/commit/23e5cbe6b090d7f22982aee909a6a618174d3c2d
- [debian-lts-announce] 20200630 [SECURITY] [DLA 2264-1] libvncserver security update mailing-list
- openSUSE-SU-2020:0988 vendor-advisory
- openSUSE-SU-2020:1025 vendor-advisory
- openSUSE-SU-2020:1056 vendor-advisory
- USN-4434-1 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1860354
- [debian-lts-announce] 20200828 [SECURITY] [DLA 2347-1] libvncserver security update mailing-list