# CVE-2026-76989: liftoff-sr CIPster out-of-bounds read in TCP encapsulation

Source: https://junglewise.ai/threats/cve-2026-76989-liftoff-sr-cipster-out-of-bounds-read-in-tcp-encapsulation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-20. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-76989 · Severity: medium · CVSS 5.3 · Published 2026-08-20

CIPster is an EtherNet/IP protocol stack library used in industrial I/O adapter devices. A flaw in the TCP encapsulation receive path allows an attacker to read memory beyond intended boundaries, potentially exposing sensitive data or causing a denial of service on affected devices.

## Quick answers

**Is CVE-2026-76989 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-76989 being exploited in the wild.

**How severe is CVE-2026-76989?** Medium severity, with a CVSS score of 5.3, published 20 August 2026.

**Which products and versions are affected?** liftoff-sr CIPster 1802525be27d33e19a9a83c163e331a1d13b1892 and earlier.

**Is there a fix for CVE-2026-76989?** A patch was published on 2026-08-20: Patch available as commit e8e9dba09bf56962807d3504b783ccdb6287f3e4 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-76989 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-76989?** Check whether anything you run is named in the advisory. 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.

## Technical details

An out-of-bounds read vulnerability exists in the TCP Encapsulation Receive Path component (source/src/enet_encap/encap.cc) of CIPster. The vulnerability is triggered through remote network interaction without requiring authentication. The out-of-bounds read could allow an attacker to access adjacent memory regions, potentially leaking sensitive information or triggering a crash. A patch has been identified (commit e8e9dba09bf56962807d3504b783ccdb6287f3e4) and deployment is recommended.

## Affected products

- liftoff-sr CIPster 1802525be27d33e19a9a83c163e331a1d13b1892 and earlier

## Timeline

- 2026-08-20: disclosed
- 2026-08-20: patched: Patch available as commit e8e9dba09bf56962807d3504b783ccdb6287f3e4

## References

- [https://github.com/liftoff-sr/CIPster/](https://github.com/liftoff-sr/CIPster/)
- [https://github.com/liftoff-sr/CIPster/commit/e8e9dba09bf56962807d3504b783ccdb6287f3e4](https://github.com/liftoff-sr/CIPster/commit/e8e9dba09bf56962807d3504b783ccdb6287f3e4)