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CVE-2026-116742VulnerabilityPublished

HTSlib through 1.24 contains a heap out-of-bounds write and read vulnerability in bgzf_index_load_hfile() in bgzf.c

Source GCVE Database

0
Authoritative record:CVE-2026-116742· Medium 4.8

Not known to be exploited · CVSS 4.8 Medium.

Data as of 27 Oct 2026, 02:27 UTC

CVSS 4.0 base score
4.8Medium
How severe the flaw is on the 0–10 CVSS scale.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 26 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
samtoolshtslibAffected
  • <=1.24
Fixed in–
GitHubhtslibpkg:github/htslibOther threatsAffected
  • <=1.24
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Until a fix is available, users should avoid processing untrusted .gzi index files or apply any vendor-recommended mitigations once published.

Description

HTSlib versions through 1.24 have a heap out-of-bounds read and write vulnerability in the function bgzf_index_load_hfile() located in bgzf.c. This flaw allows an attacker to corrupt heap memory by providing a specially crafted .gzi index entry count. Specifically, a count value of 0xFFFFFFFF causes truncation of an internal variable to zero, leading to writes beyond a zero-sized malloc buffer and an out-of-bounds read in bgzf_useek(). This can result in heap corruption or crashes in dependent tools such as samtools and bcftools.

References

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