---
id: CVE-2026-6554
title: >-
  libpcap BPF interpreter treats the offset in the 'ja L' BPF instruction as a
  signed integer to implement looping via backward jumps, but it does not limit
  the number of loop iterations
summary: >-
  libpcap BPF interpreter treats the offset in the 'ja L' BPF instruction as a
  signed integer to implement looping via backward jumps, but it does not limit
  the number of loop iterations.  In particular uncommon use cases a crafted
  filter …
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-835
vendor: The Tcpdump Group
product: libpcap
affected:
  - libpcap < 1.10.7
published: '2026-09-05'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T19:20:25.117'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-6554'
references:
  - url: >-
      https://github.com/the-tcpdump-group/libpcap/commit/ff3c83475ac303c6b681c52ad0b6e14795a8e0ce
    label: security@tcpdump.org
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6554.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-6554'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2529091'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-6554'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-6554'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00098
epssPercentile: 0.0089
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-08T15:14:56.820512Z'
ingestedAt: '2026-09-06T10:53:52.249Z'
---

## Overview

libpcap BPF interpreter treats the offset in the 'ja L' BPF instruction as a signed integer to implement looping via backward jumps, but it does not limit the number of loop iterations.  In particular uncommon use cases a crafted filter program can cause the interpreter to loop infinitely.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-09 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6554.json)