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CVE-2026-61548· NVD / CVE Program· CNA GitHub_M

Rsyslog: mmpstrucdata stack buffer overflow with oversized RFC5424 structured data

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.94% (FIRST EPSS); higher than 60.5% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: rsyslog rsyslog 8.2606.0.

Low priority for now. Upgrade to rsyslog rsyslog 8.2606.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 8.1 · v3.1—No exploit Fix available
Published
Sep 18, 2026
Updated
Sep 24, 2026
EPSS
0.9% · 60th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.9%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • rsyslog rsyslog

    • >= 7.5.4, < 8.2606.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12rsyslogfrom 0—
Debian:13rsyslogbefore 8.2504.0-1+deb13u28.2504.0-1+deb13u2
Debian:14rsyslogbefore 8.2606.0-48.2606.0-4
openSUSE:Leap 16.0rsyslogbefore 8.2502.0-160000.4.18.2502.0-160000.4.1
openSUSE:Tumbleweedrsyslogbefore 8.2606.0-1.18.2606.0-1.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSrsyslogbefore 8.2306.0-150400.5.40.18.2306.0-150400.5.40.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7rsyslogbefore 8.2406.0-150700.3.7.18.2406.0-150700.3.7.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7rsyslogbefore 8.2608.0-150700.3.24.18.2608.0-150700.3.24.1
SUSE:Linux Enterprise Server 12 SP5-LTSSrsyslogbefore 8.2106.0-8.22.18.2106.0-8.22.1
SUSE:Linux Enterprise Server 15 SP6-LTSSrsyslogbefore 8.2406.0-150600.12.16.18.2406.0-150600.12.16.1
SUSE:Linux Enterprise Server 16.0rsyslogbefore 8.2502.0-160000.4.18.2502.0-160000.4.1

Same product

rsyslog: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-17042An issue was discovered in Rsyslog v8.1908.0.
    40Plan
  • CVE-2019-17041An issue was discovered in Rsyslog v8.1908.0.
    40Plan
  • CVE-2019-17040contrib/pmdb2diag/pmdb2diag.c in Rsyslog v8.1908.0 allows out-of-bounds access because the level length is mishandled.
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-19654Aug 12, 2026 · Rsyslog: a configuration-dependent issue in rsyslog's optional imptcp input module can allow an unauthenticated remote peer to crash rsyslogd
    30Monitor
  • ← EarlierCVE-2026-55556Sep 18, 2026 · Rsyslog: Heap buffer overflow in imhttp plugin Basic Authentication handling
    32Monitor
  • Later →CVE-2026-92709Oct 22, 2026 · Rsyslog: DynFile Path Traversal → Arbitrary File Write as Root → RCE
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
rsyslog rsyslog8.2606.0 · descriptionVendor (CNA)
azl3 rsyslog 8.2308.0-6 on Azure Linux 3.0—Microsoft (MSRC)
debian:rsyslog8.2504.0-1+deb13u2 · Debian:13Package registry (OSV)
opensuse:rsyslog8.2606.0-1.1 · openSUSE:TumbleweedPackage registry (OSV)
suse:rsyslog8.2502.0-160000.4.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-121 · Stack-based Buffer Overflow

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records