CVE-2026-78002

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

State: Published
Severity: 7.5 High
Published: Aug 27, 2026
Updated: Oct 30, 2026
Reserved: Aug 21, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	redhat

Weaknesses

CWE-131 Incorrect Calculation of Buffer Size

Affected Products

Product	Versions
Red Hat Enterprise Linux 10Red Hat	0:8.2510.0-5.el10_2.2 and laterNot affected
Red Hat Enterprise Linux 10.0 Extended Update SupportRed Hat	0:8.2412.0-1.el10_0.2 and laterNot affected
Red Hat Enterprise Linux 8Red Hat	0:8.2102.0-15.el8_10.3 and laterNot affected
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportRed Hat	0:8.2102.0-7.el8_6.2 and laterNot affected
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnRed Hat	0:8.2102.0-7.el8_6.2 and laterNot affected
Red Hat Enterprise Linux 8.8 Telecommunications Update ServiceRed Hat	0:8.2102.0-13.el8_8.1 and laterNot affected
Red Hat Enterprise Linux 8.8 Update Services for SAP SolutionsRed Hat	0:8.2102.0-13.el8_8.1 and laterNot affected
Red Hat Enterprise Linux 9Red Hat	0:8.2510.0-2.el9_8.2 and laterNot affected
Red Hat Enterprise Linux 9.2 Update Services for SAP SolutionsRed Hat	0:8.2102.0-113.el9_2.3 and laterNot affected
Red Hat Enterprise Linux 9.4 Update Services for SAP SolutionsRed Hat	0:8.2310.0-4.el9_4.2 and laterNot affected
Red Hat Enterprise Linux 9.6 Extended Update SupportRed Hat	0:8.2412.0-1.el9_6.2 and laterNot affected
Red Hat Update Infrastructure 5Red Hat	1790241900 and laterNot affected
Red Hat Enterprise Linux 6Red Hat
Red Hat Enterprise Linux 6Red Hat
Red Hat Enterprise Linux 7Red Hat

References

RHSA-2026:69540vendor-advisory
RHSA-2026:69541vendor-advisory
RHSA-2026:71603vendor-advisory
RHSA-2026:80817vendor-advisory
RHSA-2026:81321vendor-advisory
RHSA-2026:84576vendor-advisory
RHSA-2026:86124vendor-advisory
RHSA-2026:87408vendor-advisory
RHSA-2026:90349vendor-advisory
RHSA-2026:91582vendor-advisory
https://access.redhat.com/security/cve/CVE-2026-78002vdb-entry
RHBZ#2521135issue-tracking
https://github.com/rsyslog/rsyslog/security/advisories/GHSA-g72f-gc6v-f2w3
http://www.openwall.com/lists/oss-security/2026/08/29/1

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