Application crash via long CNAME response double-free
Published May 7, 2026 · Updated Aug 28, 2026
Double free in Go standard library net before 1.25.10 and 1.26.0-0 through 1.26.2 allows remote attackers to crash applications. The cgoResSearch path used by LookupCNAME processes an oversized CNAME answer through the cgo DNS resolver and releases the same C allocation twice. Exploitation requires an affected Go binary to call LookupCNAME through cgo and accept an attacker-controlled DNS response; the bounded consequence is that process's crash.
Summary
What happened
Double free in Go standard library net before 1.25.10 and 1.26.0-0 through 1.26.2 allows remote attackers to crash applications. The cgoResSearch path used by LookupCNAME processes an oversized CNAME answer through the cgo DNS resolver and releases the same C allocation twice. Exploitation requires an affected Go binary to call LookupCNAME through cgo and accept an attacker-controlled DNS response; the bounded consequence is that process's crash.
The record
- CVE
- CVE-2026-33811
- Published
- May 7, 2026
- Updated
- Aug 28, 2026
- Vendor
- 389 Directory Server
- Product
- Assisted Installer for OpenShift Container Platform
- Classifications
- CWE-1341, CWE-415, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 7, 2026CVE publishedPublication date reported by the CVE source.
- Aug 28, 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
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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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