Quick answers
- Is CVE-2026-54873 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-54873 being exploited in the wild.
- How severe is CVE-2026-54873?
- Informational severity, published 29 September 2026.
- Which products and versions are affected?
- OpenSSL Versions with QUIC support prior to fix.
- Is there a fix for CVE-2026-54873?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-54873 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-54873?
- Check whether you run OpenSSL 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
The QUIC stack delays releasing packet buffer memory until stream data is copied to the application's receive buffer, as an optimization to avoid memory copies. An attacker can craft QUIC packets containing stream frames to cause the local QUIC stack to accumulate unbounded memory overhead in packet buffers (CWE-770). The fix monitors cumulative memory overhead per stream and triggers data migration to the stream buffer once overhead exceeds 64KB, limiting the exploitation window.
Affected products
- OpenSSL OpenSSL Versions with QUIC support prior to fix
Timeline
- 2026-09-29: disclosed: CVE-2026-54873 published