CVE-2026-31963

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.36% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 29.6% of scored records. A rank, not a probability.

NVD base score

8.8 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-03-18 18:22Z7 MO AGO

Last updated

2026-03-18 18:52Z7 MO AGO

Reserved

2026-03-10

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

High (CVSS 8.8)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N

Weaknesses

• CWE-122Heap-based Buffer OverflowVariant
• CWE-129Improper Validation of Array IndexVariant
• CWE-787Out-of-bounds WriteBase
• CWE-193Off-by-one ErrorBase

Data version

5.2

Document digest

bfdc2a5f542f58256c8b2e7b1c28aa0563f39bb86d3fdd3ae05a0244f3b58c6f

• github.comhttps://github.com/samtools/htslib/security/advisories/GHSA-qgqh-h2q9-7w3cx_refsource_CONFIRM
• github.comhttps://github.com/samtools/htslib/commit/8bcc9907be0f945ddc31796d64f078fa05456acdx_refsource_MISC