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TI-2026-80951 Aliases CVE-2026-116742GHSA-r296-8jjg-794r

Heap out-of-bounds write in HTSlib via truncated .gzi index count

Priority LOW 21CWE-197Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · Low · Low
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

HTSlib through 1.24 contains a numeric truncation error (CWE-197) in bgzf_index_load_hfile() that causes heap out-of-bounds writes and reads. A local attacker can corrupt heap memory or crash tools such as samtools and bcftools by getting a user to open a crafted .gzi index file.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

Description from the CNA

HTSlib through 1.24 contains a heap out-of-bounds write and read vulnerability in bgzf_index_load_hfile() in bgzf.c that allows attackers to corrupt heap memory by supplying a crafted .gzi index entry count. A count of 0xFFFFFFFF truncates noffs to zero, causing writes past a malloc(0) buffer and an offs[-1] read in bgzf_useek(), resulting in heap corruption or crashes in tools like samtools and bcftools.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00123 2nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
samtoolshtslibup to 1.24—No fix listedCNA
  • htslib Vendorsamtools Affected up to 1.24 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:htslib:htslib:*:*:*:*:*:*:*:*——Htslib
  • cpe:2.3:a:htslib:htslib:*:*:*:*:*:*:*:* Versions — — ·Htslib

Remediation

The sources list no fixed version for HTSlib.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-26 Threatist record created from CVE-2026-116742
  2. 2026-10-27 CISA SSVC decision points changed
  3. 2026-10-27 Alias added: GHSA-r296-8jjg-794r
  4. 2026-11-03 Affected versions changed · Red Hat
  5. 2026-11-03 CVSS score added · Red Hat

References

Patch 2

Advisory 1

Other 3

  • TI-2022-05532 Creation of Temporary File in Directory with Insecure Permissions CVSS 3.1HIGH 7.8
  • TI-2026-24512 HTSlib CRAM decoder vulnerable to buffer overflow CVSS 4.0HIGH 8.8
  • TI-2026-24507 HTSlib CRAM reader has heap buffer overflow due to improper validation of input CVSS 4.0HIGH 8.8
  • TI-2026-24506 HTSlib CRAM reader has heap buffer overflow due to improper validation of input CVSS 4.0HIGH 8.8
  • TI-2026-24516 samtools mpileup has use-after-free leading to an invalid read CVSS 4.0MEDIUM 6.9
  • TI-2026-24511 HTSlib CRAM reader has out-of-bounds read due to improper validation of input CVSS 4.0MEDIUM 6.9
See all 13 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences