CVE-2026-31965: medium-severity vulnerability in samtools htslib
HTSlib CRAM reader has out-of-bounds reads due to improper validation of input
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.9epss 0.4%
HTSlib is a library for reading and writing bioinformatics file formats. CRAM is a compressed format which stores DNA sequence alignment data. In the `cram_decode_slice()` function called while reading CRAM records, validation of the reference id field occurred too late, allowing two out of bounds reads to occur before the invalid data was detected. The bug does allow two values to be leaked to the caller, however as the function reports an error it may be difficult to exploit them. It is also possible that the program will crash due to trying to access invalid memory. Versions 1.23.1, 1.22.2 and 1.21.1 include fixes for this issue. There is no workaround for this issue.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
Affected products
samtools · htslibRelated CVEs — samtools htslib
In the same product, most dangerous first.
CVE-2026-31966MEDIUMHTSlib CRAM reader has out-of-bounds read due to improper validation of inputEPSS 0.5%CVE-2026-31970HIGHHTSlib BGZF index file reader has a heap buffer overflowEPSS 0.5%CVE-2026-31967MEDIUMHTSlib CRAM reader has out-of-bounds read due to improper validation of inputEPSS 0.5%CVE-2026-31968HIGHHTSlib CRAM decoder vulnerable to buffer overflowEPSS 0.4%CVE-2026-31962HIGHHTSlib CRAM reader has heap buffer overflow due to improper validation of inputEPSS 0.4%CVE-2026-31963HIGHHTSlib CRAM reader has heap buffer overflow due to improper validation of inputEPSS 0.4%