# CVE-2026-58268: SIPGO DoS via unvalidated Content-Length in stream parser

Source: https://junglewise.ai/threats/cve-2026-58268-sipgo-dos-via-unvalidated-content-length-in-stream-parser  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-22. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-58268 · Severity: high · CVSS 7.5 · Published 2026-09-22

SIPGO is a Go library used to build SIP (VoIP signaling) servers and clients. An unauthenticated attacker can send a specially crafted SIP message with a very large Content-Length header to cause the server to allocate excessive memory, crashing the service and disrupting communications.

Technologies: [github.com/emiago/sipgo (Go)](https://junglewise.ai/threats/technologies/github-com-emiago-sipgo). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-58268 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-58268 being exploited in the wild.

**How severe is CVE-2026-58268?** High severity, with a CVSS score of 7.5, published 22 September 2026.

**Which products and versions are affected?** Emiago Sipgo <= 1.4.0; github.com/emiago/sipgo (Go) <= 1.4.0, SEMVER:introduced=0,fixed=1.4.1.

**Is there a fix for CVE-2026-58268?** Yes. github.com/emiago/sipgo (Go): upgrade to 1.4.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-58268 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-58268?** Check whether you run Emiago Sipgo or github.com/emiago/sipgo (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/emiago/sipgo (Go): upgrade to 1.4.1 or later

  ```sh
  go get github.com/emiago/sipgo@v1.4.1
  ```


## Technical details

The vulnerability is a memory allocation flaw (CWE-789) in the stream parser's `parseSingle()` function. The parser allocates a buffer for the SIP message body based on the attacker-controlled Content-Length header (up to 2^32-1 bytes) without validating the size first. The size check (ParseMaxMessageLength of 65535) runs only after allocation, allowing an attacker to trigger out-of-memory conditions. The vulnerability affects all stream transports (TCP, TLS, WebSocket, WebSocket Secure) and requires no authentication or user interaction. A patch is available in version 1.4.1.

## Affected products

- emiago sipgo <= 1.4.0

## Identifiers

- CVE-2026-58268
- GHSA-pg59-5vwg-4jxq
- GO-2026-6550

## Timeline

- 2026-06-30: disclosed: Published by GitHub Advisory Database
- 2026-09-22: advisory: Updated in GitHub Advisory Database
- 2026-06-30: patched: Fix released in version 1.4.1

## References

- [https://api.github.com/users/arkark](https://api.github.com/users/arkark)

## Related threats

- [SIPGO DoS via unvalidated WebSocket frame length](https://junglewise.ai/threats/cve-2026-77322-sipgo-dos-via-unvalidated-websocket-frame-length)
- [GO-2025-4244 - SIPGO is Vulnerable to Response DoS via Nil Pointer Dereference in github.com/emiago/sipgo](https://junglewise.ai/threats/cve-2025-68274-sipgo-is-vulnerable-to-response-dos-via-nil-pointer-dereference)