Header length truncation in Linux kernel stmmac TSO path
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from CNA.
Summary
The stmmac network driver in the Linux kernel stores the TSO protocol header length in an 8-bit variable. Headers longer than 255 bytes wrap around, so a TCP over IPv6 packet carrying a few hundred bytes of sticky destination or hop-by-hop options gets an incorrect header length. Linux kernel versions from 4.13 are affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix TSO header length truncation stmmac_tso_xmit() stores the protocol header length returned by stmmac_tso_header_size() in a u8. stmmac_tso_valid_packet() admits headers up to 1023 bytes, so a header longer than 255 bytes wraps modulo 256 (486 becomes 230, 256 becomes 0). A TCP over IPv6 socket carrying a few hundred bytes of sticky destination/hop-by-hop options makes skb_tcp_all_headers() exceed 255 while staying below the 1023-byte limit, so such an skb reaches stmmac_tso_xmit(). Widen proto_hdr_len to unsigned int, which is sufficient since the value is bounded by the hardware limit, and adjust the debug print specifier accordingly.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
The fixed versions for Linux are 7.2.8 and 7.3.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 7.2.8, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-06 Threatist record created from CVE-2026-98288
- 2026-10-06 Alias added: GHSA-gg98-59cc-cfq6
- 2026-10-11 Affected versions changed · Red Hat
- 2026-10-11 CVSS score added · Red Hat
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-98288 · CVE Program
- CVE-2026-98288 · NVD
- FIRST EPSS
- GHSA-gg98-59cc-cfq6 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98288 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences