CVE-2025-68363bpf: Check skb->transport_header is set in bpf_skb_check_mtu
Updated under an hour ago ()
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It affects Linux and 3 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: bpf: Check skb->transport_header is set in bpf_skb_check_mtu The bpf_skb_check_mtu helper needs to use skb->transport_header when the BPF_MTU_CHK_SEGS flag is used: bpf_skb_check_mtu(skb, ifindex, &mtu_len, 0, BPF_MTU_CHK_SEGS) The transport_header is not always set. There is a WARN_ON_ONCE report when CONFIG_DEBUG_NET is enabled + skb->gso_size is set + bpf_prog_test_run is used: WARNING: CPU: 1 PID: 2216 at ./include/linux/skbuff.h:3071 skb_gso_validate_network_len bpf_skb_check_mtu bpf_prog_3920e25740a41171_tc_chk_segs_flag # A test in the next patch bpf_test_run bpf_prog_test_run_skb For a normal ingress skb (not test_run), skb_reset_transport_header is performed but there is plan to avoid setting it as described in commit 2170a1f09148 ("net: no longer reset transport_header in __netif_receive_skb_core()"). This patch fixes the bpf helper by checking skb_transport_header_was_set(). The check is done just before skb->transport_header is used, to avoid breaking the existing bpf prog. The WARN_ON_ONCE is limited to bpf_prog_test_run, so targeting bpf-next.
- CVSS
- Not yet scored
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Deferred
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 34b2021cc61642d61c3cf943d9e71925b827941b before b3171a5e4622e915e94599a55f4964078bdec27e; from 34b2021cc61642d61c3cf943d9e71925b827941b before 97b876fa88322625228792cf7a5fd77531815a80; 34b2021cc61642d61c3cf943d9e71925b827941b builds before 30ce906557a21adef4cba5901c8e995dc18263a9; 34b2021cc61642d61c3cf943d9e71925b827941b builds before 1c30e4afc5507f0069cc09bd561e510e4d97fbf7; from 34b2021cc61642d61c3cf943d9e71925b827941b before 942268e2726ac7f16e3ec49dbfbbbe7cf5af9da5; from 34b2021cc61642d61c3cf943d9e71925b827941b before d946f3c98328171fa50ddb908593cf833587f725 | CNA record |
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
References
- https://git.kernel.org/stable/c/b3171a5e4622e915e94599a55f4964078bdec27e
- https://git.kernel.org/stable/c/97b876fa88322625228792cf7a5fd77531815a80
- https://git.kernel.org/stable/c/30ce906557a21adef4cba5901c8e995dc18263a9
- https://git.kernel.org/stable/c/1c30e4afc5507f0069cc09bd561e510e4d97fbf7
- https://git.kernel.org/stable/c/942268e2726ac7f16e3ec49dbfbbbe7cf5af9da5
- https://git.kernel.org/stable/c/d946f3c98328171fa50ddb908593cf833587f725
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.