Command crash via unchecked compression header decode
Published Mar 18, 2026 · Updated Mar 18, 2026
NULL pointer dereference in Samtools 1.17 through 1.21, 1.22 through 1.22.1, and 1.23 allows attackers to crash cram-size via malformed CRAM input. cram_size() passes a failed cram_decode_compression_header() result onward without checking for NULL, and later code dereferences it. Exploitation requires the cram-size command to process an invalid CRAM header; the resulting failure interrupts that command-line process rather than the host system.
Summary
What happened
NULL pointer dereference in Samtools 1.17 through 1.21, 1.22 through 1.22.1, and 1.23 allows attackers to crash cram-size via malformed CRAM input. cram_size() passes a failed cram_decode_compression_header() result onward without checking for NULL, and later code dereferences it. Exploitation requires the cram-size command to process an invalid CRAM header; the resulting failure interrupts that command-line process rather than the host system.
The record
- CVE
- CVE-2026-31973
- Published
- Mar 18, 2026
- Updated
- Mar 18, 2026
- Vendor
- Samtools
- Product
- Samtools
- Classifications
- CWE-476
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 18, 2026CVE publishedPublication date reported by the CVE source.
- Mar 18, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 1.17, < 1.21.1
- Affected versionversion=>= 1.22, < 1.22.2
- Affected versionversion== 1.23
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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