Rsyslog: rsyslog: denial of service via heap buffer overflow in rainerscript replace() function
Priority MEDIUM 41CWE-131Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 14 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-131 and the CVSS impact.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01064 64th percentileScored 2026-11-07
Fix Partial Red Hat: 11 advisoriesRed Hat: 14 fixed, 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | 8.2510.0-5.el10_2.2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | — | 8.2412.0-1.el10_0.2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | 8.2102.0-15.el8_10.3 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | — | 8.1911.0-7.el8_4.5 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | — | 8.1911.0-7.el8_4.5 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | — | 8.2102.0-7.el8_6.2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | — | 8.2102.0-7.el8_6.2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | — | 8.2102.0-13.el8_8.1 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | — | 8.2102.0-13.el8_8.1 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 8.2510.0-2.el9_8.2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | — | 8.2102.0-113.el9_2.3 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | — | 8.2310.0-4.el9_4.2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | — | 8.2412.0-1.el9_6.2 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1790241900 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in 8.2510.0-5.el10_2.2 Patch available CNA
- Red Hat Enterprise Linux 10.0 Extended Update Support VendorRed Hat Affected — Fixed in 8.2412.0-1.el10_0.2 Patch available CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 8.2102.0-15.el8_10.3 Patch available CNA
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support VendorRed Hat Affected — Fixed in 8.1911.0-7.el8_4.5 Patch available CNA
- Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On VendorRed Hat Affected — Fixed in 8.1911.0-7.el8_4.5 Patch available CNA
- Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support VendorRed Hat Affected — Fixed in 8.2102.0-7.el8_6.2 Patch available CNA
- Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On VendorRed Hat Affected — Fixed in 8.2102.0-7.el8_6.2 Patch available CNA
- Red Hat Enterprise Linux 8.8 Telecommunications Update Service VendorRed Hat Affected — Fixed in 8.2102.0-13.el8_8.1 Patch available CNA
- Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 8.2102.0-13.el8_8.1 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 8.2510.0-2.el9_8.2 Patch available CNA
- Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 8.2102.0-113.el9_2.3 Patch available CNA
- Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 8.2310.0-4.el9_4.2 Patch available CNA
- Red Hat Enterprise Linux 9.6 Extended Update Support VendorRed Hat Affected — Fixed in 8.2412.0-1.el9_6.2 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1790241900 Patch available CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE names CNA · 16
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/o:redhat:enterprise_linux:10.2 | 10.2 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux_eus:10.0 | 10.0 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:8::appstream | 8 | — | Red Hat |
| cpe:/a:redhat:rhel_aus:8.4::appstream | 8.4 | — | Red Hat |
| cpe:/a:redhat:rhel_eus_long_life:8.4::appstream | 8.4 | — | Red Hat |
| cpe:/a:redhat:rhel_aus:8.6::appstream | 8.6 | — | Red Hat |
| cpe:/a:redhat:rhel_eus_long_life:8.6::appstream | 8.6 | — | Red Hat |
| cpe:/a:redhat:rhel_e4s:8.8::appstream | 8.8 | — | Red Hat |
| cpe:/a:redhat:rhel_tus:8.8::appstream | 8.8 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:9::appstream | 9 | — | Red Hat |
- cpe:/o:redhat:enterprise_linux:10.2 Versions 10.2 — ·Red Hat
- cpe:/o:redhat:enterprise_linux_eus:10.0 Versions 10.0 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:8::appstream Versions 8 — ·Red Hat
- cpe:/a:redhat:rhel_aus:8.4::appstream Versions 8.4 — ·Red Hat
- cpe:/a:redhat:rhel_eus_long_life:8.4::appstream Versions 8.4 — ·Red Hat
- cpe:/a:redhat:rhel_aus:8.6::appstream Versions 8.6 — ·Red Hat
- cpe:/a:redhat:rhel_eus_long_life:8.6::appstream Versions 8.6 — ·Red Hat
- cpe:/a:redhat:rhel_e4s:8.8::appstream Versions 8.8 — ·Red Hat
- cpe:/a:redhat:rhel_tus:8.8::appstream Versions 8.8 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:9::appstream Versions 9 — ·Red Hat
Show 6 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/a:redhat:rhel_e4s:9.2::appstream | 9.2 | — | Red Hat |
| cpe:/a:redhat:rhel_e4s:9.4::appstream | 9.4 | — | Red Hat |
| cpe:/a:redhat:rhel_eus:9.6::appstream | 9.6 | — | Red Hat |
| cpe:/a:redhat:rhui:5::el9 | 5 | — | Red Hat |
| cpe:/o:redhat:rhel_els:6 | 6 | — | Red Hat |
| cpe:/o:redhat:rhel_els:7 | 7 | — | Red Hat |
- cpe:/a:redhat:rhel_e4s:9.2::appstream Versions 9.2 — ·Red Hat
- cpe:/a:redhat:rhel_e4s:9.4::appstream Versions 9.4 — ·Red Hat
- cpe:/a:redhat:rhel_eus:9.6::appstream Versions 9.6 — ·Red Hat
- cpe:/a:redhat:rhui:5::el9 Versions 5 — ·Red Hat
- cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
- cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat
Remediation
Red Hat 11 advisories
- RHSA-2026:95573 Released 2026-11-05 · Red Hat rating Importantrsyslog security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) rsyslog-8.1911.0-7.el8_4.5, rsyslog-crypto-8.1911.0-7.el8_4.5, rsyslog-elasticsearch-8.1911.0-7.el8_4.5 +14
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) rsyslog-8.1911.0-7.el8_4.5, rsyslog-crypto-8.1911.0-7.el8_4.5, rsyslog-elasticsearch-8.1911.0-7.el8_4.5 +14
- RHSA-2026:91582 Released 2026-10-28 · Red Hat rating Importantrsyslog security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) rsyslog-8.2102.0-7.el8_6.2, rsyslog-crypto-8.2102.0-7.el8_6.2, rsyslog-elasticsearch-8.2102.0-7.el8_6.2 +16
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) rsyslog-8.2102.0-7.el8_6.2, rsyslog-crypto-8.2102.0-7.el8_6.2, rsyslog-elasticsearch-8.2102.0-7.el8_6.2 +16
- RHSA-2026:90349 Released 2026-10-26 · Red Hat rating Importantrsyslog security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) rsyslog-8.2310.0-4.el9_4.2, rsyslog-crypto-8.2310.0-4.el9_4.2, rsyslog-elasticsearch-8.2310.0-4.el9_4.2 +17
Show 8 more Red Hat advisories
- RHSA-2026:87408 Released 2026-10-21 · Red Hat rating Importantrsyslog security update
- Red Hat Enterprise Linux AppStream E4S (v.8.8) rsyslog-8.2102.0-13.el8_8.1, rsyslog-crypto-8.2102.0-13.el8_8.1, rsyslog-elasticsearch-8.2102.0-13.el8_8.1 +16
- Red Hat Enterprise Linux AppStream TUS (v.8.8) rsyslog-8.2102.0-13.el8_8.1, rsyslog-crypto-8.2102.0-13.el8_8.1, rsyslog-elasticsearch-8.2102.0-13.el8_8.1 +16
- RHSA-2026:86124 Released 2026-10-20 · Red Hat rating Importantrsyslog security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) rsyslog-8.2102.0-113.el9_2.3, rsyslog-crypto-8.2102.0-113.el9_2.3, rsyslog-elasticsearch-8.2102.0-113.el9_2.3 +17
- RHSA-2026:84576 Released 2026-10-19 · Red Hat rating Importantrsyslog security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) rsyslog-8.2412.0-1.el9_6.2, rsyslog-crypto-8.2412.0-1.el9_6.2, rsyslog-elasticsearch-8.2412.0-1.el9_6.2 +17
- RHSA-2026:81321 Released 2026-10-12 · Red Hat rating Importantrsyslog security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) rsyslog-8.2412.0-1.el10_0.2, rsyslog-crypto-8.2412.0-1.el10_0.2, rsyslog-doc-8.2412.0-1.el10_0.2 +17
- RHSA-2026:80817 Released 2026-10-12 · Red Hat rating Importantrsyslog security update
- Red Hat Enterprise Linux AppStream (v. 8) rsyslog-8.2102.0-15.el8_10.3, rsyslog-doc-8.2102.0-15.el8_10.3
- RHSA-2026:71603 Released 2026-09-24 · Red Hat rating ImportantRed Hat Update Infrastructure 5.3 security update
- Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-rhel9, registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9 +2
- RHSA-2026:69540 Released 2026-09-22 · Red Hat rating Importantrsyslog security update
- Red Hat Enterprise Linux AppStream (v. 9) rsyslog-8.2510.0-2.el9_8.2, rsyslog-crypto-8.2510.0-2.el9_8.2, rsyslog-doc-8.2510.0-2.el9_8.2 +18
- RHSA-2026:69541 Released 2026-09-21 · Red Hat rating Importantrsyslog security update
- Red Hat Enterprise Linux AppStream (v. 10) rsyslog-8.2510.0-5.el10_2.2, rsyslog-crypto-8.2510.0-5.el10_2.2, rsyslog-doc-8.2510.0-5.el10_2.2 +17
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:69541 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:80817 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:69540 |
| Red Hat Enterprise Linux AppStream AUS (v.8.4) | Fixed | RHSA-2026:95573 |
| Red Hat Enterprise Linux AppStream AUS (v.8.6) | Fixed | RHSA-2026:91582 |
| Red Hat Enterprise Linux AppStream E4S (v.8.8) | Fixed | RHSA-2026:87408 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:86124 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:90349 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:81321 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:84576 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) | Fixed | RHSA-2026:95573 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) | Fixed | RHSA-2026:91582 |
| Red Hat Enterprise Linux AppStream TUS (v.8.8) | Fixed | RHSA-2026:87408 |
| Red Hat Update Infrastructure 5 | Fixed | RHSA-2026:71603 |
Not affected: 13 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux AppStream (v. 8)
- Red Hat Enterprise Linux AppStream AUS (v.8.4)
- Red Hat Enterprise Linux AppStream AUS (v.8.6)
- Red Hat Enterprise Linux AppStream E4S (v.8.8)
- Red Hat Enterprise Linux AppStream E4S (v.9.2)
- Red Hat Enterprise Linux AppStream E4S (v.9.4)
- Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- Red Hat Enterprise Linux AppStream EUS (v.9.6)
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)
- Red Hat Enterprise Linux AppStream TUS (v.8.8)
- Red Hat Update Infrastructure 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-78002
- 2026-10-12 Fix available: rsyslog@0:8.2412.0-1.el10_0.2 · CNA
- 2026-10-12 1 new reference · CNA
- 2026-10-12 Fix available: RHSA-2026:81321 · Red Hat
- 2026-10-12 Fix available: rsyslog@0:8.2102.0-15.el8_10.3 · CNA
- 2026-10-12 1 new reference · CNA
- 2026-10-13 Fix available: RHSA-2026:80817 · Red Hat
- 2026-10-13 Fix available: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux AppStream EUS (v. 10.0) · Red Hat
- 2026-10-19 Fix available: rsyslog@0:8.2412.0-1.el9_6.2 · CNA
- 2026-10-19 1 new reference · CNA
- 2026-10-19 Fix available: RHSA-2026:84576 · Red Hat
- 2026-10-19 Fix available: Red Hat Enterprise Linux AppStream EUS (v.9.6) · Red Hat
- 2026-10-21 Fix available: rsyslog@0:8.2102.0-113.el9_2.3 · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-21 Fix available: RHSA-2026:86124 · Red Hat
- 2026-10-21 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.2) · Red Hat
- 2026-10-21 Fix available: rsyslog@0:8.2102.0-13.el8_8.1 · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-22 Fix available: RHSA-2026:87408 · Red Hat
- 2026-10-22 Fix available: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · Red Hat
- 2026-10-26 Fix available: rsyslog@0:8.2310.0-4.el9_4.2 · CNA
- 2026-10-26 1 new reference · CNA
- 2026-10-26 Fix available: RHSA-2026:90349 · Red Hat
- 2026-10-26 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.4) · Red Hat
- 2026-10-30 Fix available: rsyslog@0:8.2102.0-7.el8_6.2 · CNA
- 2026-10-30 1 new reference · CNA
- 2026-10-30 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) · Red Hat
- 2026-11-05 Fix available: rsyslog@0:8.1911.0-7.el8_4.5 · CNA
- 2026-11-05 1 new reference · CNA
- 2026-11-05 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) · Red Hat
- 2026-11-06 Fix available: RHSA-2026:91582 · Red Hat
- 2026-11-06 Fix available: RHSA-2026:95573 · Red Hat
References
Advisory 11
More Red Hat vulnerabilities
- TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
- TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
- TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
- TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
- TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-78002 · CVE Program
- CVE-2026-78002 · NVD
- FIRST EPSS
- CVE-2026-78002 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences