Is CVE-2026-13589 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-13589 being exploited in the wild.

How severe is CVE-2026-13589?

Medium severity, with a CVSS score of 5.6, published 29 June 2026.

Is there a fix for CVE-2026-13589?

A patch was published on 2026-06-24: Fix merged into dev branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-13589 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-13589?

Check whether you run Seladb PcapPlusPlus 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.

CVE-2026-13589: seladb PcapPlusPlus heap buffer overflow in TelnetLayer

CVE-2026-13589 · Severity: medium · CVSS 5.6 · Published 2026-06-29

PcapPlusPlus is a C++ library used for capturing and analyzing network traffic. A security flaw in how the library handles Telnet network data could allow a remote attacker to send specially crafted, malformed packets that cause the application using this library to crash. This could lead to a denial of service, impacting the availability of network monitoring or security tools that rely on PcapPlusPlus.

Technologies: Seladb PcapPlusPlus. Vendors: Seladb.

Quick answers

Is CVE-2026-13589 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-13589 being exploited in the wild.
How severe is CVE-2026-13589?: Medium severity, with a CVSS score of 5.6, published 29 June 2026.
Which products and versions are affected?: Seladb PcapPlusPlus 25.05.
Is there a fix for CVE-2026-13589?: A patch was published on 2026-06-24: Fix merged into dev branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-13589 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-13589?: Check whether you run Seladb PcapPlusPlus 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.

Technical details

A heap-based buffer overflow (out-of-bounds read) exists in the Telnet Subnegotiation Packet Handler of PcapPlusPlus 25.05. The vulnerability is located in the `pcpp::TelnetLayer::getSubCommand` function within `Packet++/src/TelnetLayer.cpp`. The root cause is a failure to rigorously verify buffer lengths when processing truncated Telnet packets; specifically, the code attempts to access memory at an offset of 2 without ensuring the buffer length is at least 3 bytes. A remote attacker can exploit this by sending malformed Telnet packets, potentially leading to a program crash (Denial of Service). A patch has been released in commit 98e671010bc7c87b95898c22ae289220ae92542b.

Affected products

seladb PcapPlusPlus 25.05

Timeline

2026-05-25: disclosed: Issue reported on GitHub repository
2026-06-24: patched: Fix merged into dev branch
2026-06-29: advisory: NVD publication date

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.