Memory corruption via stale decompressor input pointer
Published Apr 13, 2026 · Updated Aug 13, 2026
Use-after-free in CPython before 3.15.0 allows remote attackers to read or write process memory through reused decompressors. The _lzma, _bz2, and zlib decompression error paths release the caller buffer after MemoryError but leave next_in pointing to that freed memory. Exploitation requires memory pressure and a program that reuses the same decompressor after MemoryError; one-shot helper functions are unaffected.
Summary
What happened
Use-after-free in CPython before 3.15.0 allows remote attackers to read or write process memory through reused decompressors. The _lzma, _bz2, and zlib decompression error paths release the caller buffer after MemoryError but leave next_in pointing to that freed memory. Exploitation requires memory pressure and a program that reuses the same decompressor after MemoryError; one-shot helper functions are unaffected.
The record
- CVE
- CVE-2026-6100
- Published
- Apr 13, 2026
- Updated
- Aug 13, 2026
- Vendor
- 389 Directory Server
- Product
- RHEL-8 based Middleware Containers
- Classifications
- CWE-416, CWE-787
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 13, 2026CVE publishedPublication date reported by the CVE source.
- Aug 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
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
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo