DPDK GSO library: Out-of-bounds read and write in GSO header copy
Summary
A flaw in the software Generic Segmentation Offload (GSO) code of the DPDK library allows header data to be copied without proper size checks. A remote attacker or a guest virtual machine can send crafted packets that cause out-of-bounds reads and writes in heap memory. This can crash the DPDK application or potentially lead to code execution, without authentication. The issue only applies where software GSO processes untrusted traffic.
Affected
- DPDK applications using software GSO (rte_gso_segment, testpmd --enable-gso)
- Red Hat Fast Datapath for RHEL 8, 9 and 10 (listed as affected by Red Hat)
- Affected DPDK versions: Unknown.
Fixed in
- Unknown. Red Hat's advisory does not list fixed versions in the sources reviewed.
- Debian DSA-6597-1 (31 Oct 2026) is linked to this CVE; the trixie fix is reported as 24.11.8-0+deb13u1, not yet confirmed for this CVE.
- Ubuntu: Needs evaluation.
Workaround
- Do not run software GSO on untrusted packets.
- Sizing the direct mbuf pool above the maximum header size (about 208 bytes for tunneled traffic) is suggested by a secondary source; it does not fully cover the short-first-segment over-read and is unverified.
Exploitation
- CISA KEV: not listed; no known exploitation.
- EPSS about 0.33%.
- No public proof of concept found.
- CISA SSVC: exploitation none, automatable yes, technical impact partial.
Our recommendation
- Check whether DPDK, OVS-DPDK or Red Hat Fast Datapath is in use and whether software GSO is enabled.
- Apply vendor updates as soon as they are confirmed for your platform.
- Until patched, avoid software GSO on untrusted or guest-originated traffic.
- Monitor vendor advisories for confirmed fixed versions.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Red Hat CVE record CVE-2026-100236 access.redhat.com
- Red Hat Bugzilla 2541488 bugzilla.redhat.com
- Debian security tracker www.debian.org
- Ubuntu CVE page ubuntu.com
- OpenCVE CVE-2026-100236 app.opencve.io
- VulDB 420087 vuldb.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 08:11.
Original description (NVD)
A flaw was found in the DPDK GSO library. When software GSO copies packet headers into a new mbuf, it does not check that the header fits in the source first segment or in the destination buffer, and a header longer than the configured GSO segment size can underflow the payload-size calculation. A remote or guest-supplied packet processed with software GSO can trigger an out-of-bounds read or write.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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