Out-of-bounds Read in The Tcpdump Group Libpcap
CVE-2026-31912
libpcap BPF interpreter detects neither reaching the end of the filter program buffer due to lack of a return instruction nor executing a jump instruction with an offset that translates to a pointer outside of the buffer. In particular uncommon use cases a crafted filter program can cause the interpreter to try reading the OS process memory in the 32GiB around the buffer on 64-bit architectures and in the entire address space on 32-bit architectures.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.001 (1.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 1.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-31912?
- CVE-2026-31912 is a medium-severity vulnerability in The Tcpdump Group Libpcap, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2026-09-05.
- How severe is CVE-2026-31912?
- Medium severity. CVSS v3 base score is 5.5 out of 10.