CVE-2026-78002

Rsyslog: rsyslog: denial of service via heap buffer overflow in rainerscript replace() function

HIGH
7.5
CVSS Score
Published: August 27, 2026 at 04:12 PM UTC
Updated: October 26, 2026 at 05:17 PM UTC
1 product affected across 1 vendorEnterprise Linux

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Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

A flaw was found in rsyslog. An unauthenticated remote attacker can trigger a heap buffer overflow in the RainerScript `replace()` function by sending specially crafted syslog messages. This vulnerability arises from an incorrect buffer size calculation during string replacement, causing memory corruption. Successful exploitation can lead to a denial of service (DoS) for the affected system.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions7
Vendor states this is fixed in 0:8.2102.0-113.el9_2.3 (unaffected)
Vendor states this is fixed in 0:8.2102.0-13.el8_8.1 (unaffected)
Vendor states this is fixed in 0:8.2102.0-15.el8_10.3 (unaffected)
Vendor states this is fixed in 0:8.2412.0-1.el10_0.2 (unaffected)
Vendor states this is fixed in 0:8.2412.0-1.el9_6.2 (unaffected)
Vendor states this is fixed in 0:8.2510.0-2.el9_8.2 (unaffected)
Vendor states this is fixed in 0:8.2510.0-5.el10_2.2 (unaffected)
Vendor states this is fixed in 6 (unaffected)

References (13)

VDB Entryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-78002
Issue Trackingx_refsource_REDHAT
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2521135
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2026/08/29/1
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:69541
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:69540
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:71603
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:81321

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-131

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