High

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

Type: advisorySource: Official CVE List1 source record

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.

Announced 27 Aug 2026Source revision 1

Original source ↗

CVE-2026-78002

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-78002

Red Hat Enterprise Linux 10

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 10.0 Extended Update Support

Source reference: /containers/cna/affected/1/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 8

Source reference: /containers/cna/affected/2/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 8.8 Telecommunications Update Service

Source reference: /containers/cna/affected/3/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

Source reference: /containers/cna/affected/4/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 9

Source reference: /containers/cna/affected/5/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Source reference: /containers/cna/affected/6/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 9.6 Extended Update Support

Source reference: /containers/cna/affected/7/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Update Infrastructure 5

Source reference: /containers/cna/affected/8/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 6

Source reference: /containers/cna/affected/9/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 6

Source reference: /containers/cna/affected/10/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 7

Source reference: /containers/cna/affected/11/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:10.2"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 10",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:8.2510.0-5.el10_2.2",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux_eus:10.0"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 10.0 Extended Update Support",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:8.2412.0-1.el10_0.2",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:enterprise_linux:8::appstream"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 8",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:8.2102.0-15.el8_10.3",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:rhel_e4s:8.8::appstream",
      "cpe:/a:redhat:rhel_tus:8.8::appstream"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 8.8 Telecommunications Update Service",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:8.2102.0-13.el8_8.1",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:rhel_e4s:8.8::appstream",
      "cpe:/a:redhat:rhel_tus:8.8::appstream"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:8.2102.0-13.el8_8.1",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:enterprise_linux:9::appstream"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 9",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:8.2510.0-2.el9_8.2",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:rhel_e4s:9.2::appstream"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:8.2102.0-113.el9_2.3",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:rhel_eus:9.6::appstream"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 9.6 Extended Update Support",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:8.2412.0-1.el9_6.2",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:rhui:5::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Update Infrastructure 5",
    "versions": [
      {
        "status": "unaffected",
        "version": "1790241900",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rhui5/haproxy-rhel9",
    "collectionURL": "https://catalog.redhat.com/software/containers/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:6"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 6",
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:6"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 6",
    "packageName": "rsyslog7",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:7"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 7",
    "packageName": "rsyslog",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  }
]

Related CVEs: CVE-2026-78002
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #49940 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 13:58:40 GMT
Publisher date: Thu, 27 Aug 2026 16:12:59 GMT

Read the original announcement