Description
Rsyslog is a rocket-fast system for log processing. From 7.5.4 until 8.2606.0, the optional mmpstrucdata plugin's parseSD_PARAM function in plugins/mmpstrucdata/mmpstrucdata.c stores RFC5424 parameter values in a fixed pVal[32 * 1024] stack buffer and calls parsePARAM_VALUE without supplying the destination size. A remote unauthenticated attacker whose crafted RFC5424 message reaches an action using mmpstrucdata can provide a structured-data parameter larger than that buffer when MaxMessageSize permits it, causing an attacker-controlled stack overwrite. Deployments that do not install and use the plugin, or whose effective message-size limit remains below the required threshold, are not affected by this issue. The demonstrated impact is a crash and interruption of log collection; code execution is not demonstrated. This issue is fixed in version 8.2606.0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| rsyslog | rsyslog | >= 7.5.4, < 8.2606.0 | — |
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 | rsyslog | 8.2606.0-4 | — |
| Debian 13 | rsyslog | 8.2504.0-1+deb13u2 | — |
| Debian 12 | rsyslog | 8.2302.0-1+deb12u2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | rsyslog | 8.2512.0-1ubuntu4.1 | USN-8598-1 |
| Ubuntu 24.04 LTS | rsyslog | 8.2312.0-3ubuntu9.3 | USN-8598-1 |
| Ubuntu 22.04 LTS | rsyslog | 8.2112.0-2ubuntu2.4 | USN-8598-1 |
| Ubuntu 14.04 LTS | rsyslog | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | rsyslog | No fix yet | — |
| Ubuntu Pro 18.04 LTS | rsyslog | No fix yet | — |
| Ubuntu Pro 16.04 LTS | rsyslog | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | rsyslog | 8.2406.0-150700.3.7.1 | SUSE-SU-2026:4611-1, SUSE-SU-2026:3478-1 |
| SLES 15 SP6 | rsyslog | 8.2406.0-150600.12.16.1 | SUSE-SU-2026:3442-1 |
| SLES 15 SP5 | rsyslog | 8.2306.0-150400.5.40.1 | SUSE-SU-2026:3518-1 |
| SLES 15 SP4 | rsyslog | 8.2306.0-150400.5.40.1 | SUSE-SU-2026:3518-1 |
| SLES 12 SP5 | rsyslog | 8.2106.0-8.22.1 | SUSE-SU-2026:3498-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | rsyslog | 8.2502.0-160000.4.1 | SUSE-SU-2026:24598-1, SUSE-SU-2026:23145-1, SUSE-SU-2026:23122-1 |
| SLES for SAP 15 SP6 | rsyslog | 8.2406.0-150600.12.16.1 | SUSE-SU-2026:3442-1 |
| SLES for SAP 15 SP5 | rsyslog | 8.2306.0-150400.5.40.1 | SUSE-SU-2026:3518-1 |
| SLES for SAP 15 SP4 | rsyslog | 8.2306.0-150400.5.40.1 | SUSE-SU-2026:3518-1 |
| SLES 16.0 | rsyslog | 8.2502.0-160000.4.1 | SUSE-SU-2026:24598-1, SUSE-SU-2026:23145-1, SUSE-SU-2026:23122-1 |
| SLE HPC 15 SP5 | rsyslog | 8.2306.0-150400.5.40.1 | SUSE-SU-2026:3518-1 |
| SLE HPC 15 SP4 | rsyslog | 8.2306.0-150400.5.40.1 | SUSE-SU-2026:3518-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | rsyslog | 8.2606.0-1.1 | openSUSE-SU-2026:11407-1 |
| openSUSE Leap 16.0 | rsyslog | 8.2502.0-160000.4.1 | openSUSE-SU-2026:22184-1, openSUSE-SU-2026:21535-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | rsyslog | 8.2608.0-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | rsyslog | No fix yet | — |
Advisories 13
- WID-SEC-2026-2421 rsyslog: Schwachstelle ermöglicht Denial of Service und potenziell Codeausführung BSI CERT-Bund (WID) · Nov 12, 2026
- SUSE-SU-2026:24598-1 Security update for rsyslog SUSE / openSUSE Security Updates · Nov 10, 2026
- openSUSE-SU-2026:22184-1 Security update for rsyslog SUSE / openSUSE Security Updates · Oct 31, 2026
- SUSE-SU-2026:4611-1 Security update for rsyslog SUSE / openSUSE Security Updates · Oct 10, 2026
- USN-8598-1 rsyslog vulnerabilities Ubuntu Security Notices (USN) · Sep 21, 2026
- SUSE-SU-2026:23122-1 Security update for rsyslog SUSE / openSUSE Security Updates · Aug 14, 2026
- SUSE-SU-2026:23145-1 Security update for rsyslog SUSE / openSUSE Security Updates · Aug 14, 2026
- SUSE-SU-2026:3518-1 Security update for rsyslog SUSE / openSUSE Security Updates · Aug 7, 2026
- openSUSE-SU-2026:21535-1 Security update for rsyslog SUSE / openSUSE Security Updates · Aug 6, 2026
- SUSE-SU-2026:3478-1 Security update for rsyslog SUSE / openSUSE Security Updates · Aug 5, 2026
- SUSE-SU-2026:3498-1 Security update for rsyslog SUSE / openSUSE Security Updates · Aug 5, 2026
- SUSE-SU-2026:3442-1 Security update for rsyslog SUSE / openSUSE Security Updates · Aug 3, 2026
- openSUSE-SU-2026:11407-1 rsyslog-8.2606.0-1.1 on GA media SUSE / openSUSE Security Updates · Jul 30, 2026