What’s Vulnerable › Vulnerabilities
CVE-2026-78002: Rsyslog: rsyslog: denial of service via heap buffer overflow in rainerscript replace() function
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.0% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-27 · updated 2026-10-30
- Weakness: CWE-131
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 products
- Red Hat Enterprise Linux 10: all versions — fixed in 0:8.2510.0-5.el10_2.2
- Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:8.2412.0-1.el10_0.2
- Red Hat Enterprise Linux 7: all versions
- Red Hat Enterprise Linux 8: all versions — fixed in 0:8.2102.0-15.el8_10.3
- Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 0:8.2102.0-7.el8_6.2
- Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: all versions — fixed in 0:8.2102.0-7.el8_6.2
- Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 0:8.2102.0-13.el8_8.1
- Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 0:8.2102.0-13.el8_8.1
- Red Hat Enterprise Linux 9: all versions — fixed in 0:8.2510.0-2.el9_8.2
- Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:8.2102.0-113.el9_2.3
- Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions: all versions — fixed in 0:8.2310.0-4.el9_4.2
- Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:8.2412.0-1.el9_6.2
- Red Hat Update Infrastructure 5: all versions — fixed in 1790241900
How to fix
Upgrade to a fixed version: Red Hat Enterprise Linux 10 0:8.2510.0-5.el10_2.2; Red Hat Enterprise Linux 10.0 Extended Update Support 0:8.2412.0-1.el10_0.2; Red Hat Enterprise Linux 8 0:8.2102.0-15.el8_10.3; Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:8.2102.0-7.el8_6.2; Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:8.2102.0-7.el8_6.2; Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:8.2102.0-13.el8_8.1; Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:8.2102.0-13.el8_8.1; Red Hat Enterprise Linux 9 0:8.2510.0-2.el9_8.2; Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:8.2102.0-113.el9_2.3; Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:8.2310.0-4.el9_4.2; Red Hat Enterprise Linux 9.6 Extended Update Support 0:8.2412.0-1.el9_6.2; Red Hat Update Infrastructure 5 1790241900. Check the vendor advisory for mitigations.
References
- https://access.redhat.com/errata/RHSA-2026:69540
- https://access.redhat.com/errata/RHSA-2026:69541
- https://access.redhat.com/errata/RHSA-2026:71603
- https://access.redhat.com/errata/RHSA-2026:80817
- https://access.redhat.com/errata/RHSA-2026:81321
- https://access.redhat.com/errata/RHSA-2026:84576
- https://access.redhat.com/errata/RHSA-2026:86124
- https://access.redhat.com/errata/RHSA-2026:87408
- https://access.redhat.com/errata/RHSA-2026:90349
- https://access.redhat.com/errata/RHSA-2026:91582
- https://access.redhat.com/security/cve/CVE-2026-78002
- https://bugzilla.redhat.com/show_bug.cgi?id=2521135
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