Unauthenticated service crash via undersized replacement buffer
Published Aug 27, 2026 · Updated Aug 27, 2026
Heap buffer overflow in rsyslog on Red Hat Enterprise Linux 6 through 10 allows remote attackers to crash rsyslogd via syslog messages. The RainerScript replace() implementation, also used by three-argument wrap(), underallocates its output buffer on certain partial matches before writing replacement data. Exposure requires a network input and a ruleset that applies either function to attacker-controlled message content; the demonstrated consequence is logging-service termination only.
Summary
What happened
Heap buffer overflow in rsyslog on Red Hat Enterprise Linux 6 through 10 allows remote attackers to crash rsyslogd via syslog messages. The RainerScript replace() implementation, also used by three-argument wrap(), underallocates its output buffer on certain partial matches before writing replacement data. Exposure requires a network input and a ruleset that applies either function to attacker-controlled message content; the demonstrated consequence is logging-service termination only.
The record
- CVE
- CVE-2026-78002
- Published
- Aug 27, 2026
- Updated
- Aug 27, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 6
- Classifications
- CWE-131, CWE-122, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 27, 2026CVE publishedPublication date reported by the CVE source.
- Aug 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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