CVE-2026-74612: veth: fix skb length accounting after XDP frag adjustment
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.5%
EPSS score, percentile 42.1 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 10.0 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 5.18
Unaffected before 5.18; 6.1.184; 6.6.152; 6.12.104; 6.18.45; 7.1.9; and 1 more
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 718a18a0c8a6 to before 0c3024afabb8 |
| Affected | from 718a18a0c8a6 to before 2f2a7f3f8b9f |
| Affected | from 718a18a0c8a6 to before 41b96667d42b |
| Affected | from 718a18a0c8a6 to before cdf745b7a777 |
| Affected | from 718a18a0c8a6 to before 3205b0652a37 |
| Affected | from 718a18a0c8a6 to before cb6379feaaff |
Versions not listed are: unaffected.
| Status | Versions |
|---|---|
| Affected | 5.18 |
| Unaffected | before 5.18 |
| Unaffected | 6.1.184 |
| Unaffected | 6.6.152 |
| Unaffected | 6.12.104 |
| Unaffected | 6.18.45 |
| Unaffected | 7.1.9 |
| Unaffected | 7.2 |
Versions not listed are: affected.
Versions the record lists as unaffected: 6.1.184, 6.6.152, 6.12.104, 6.18.45, 7.1.9, 7.2.
Source: CVE List, as of . About the data.
About this vulnerability
In the Linux kernel, the following vulnerability has been resolved: veth: fix skb length accounting after XDP frag adjustment veth exposes non-linear skb fragments through an xdp_buff. If an XDP program adjusts the fragment area, veth_xdp_rcv_skb() copies xdp_frags_size back to skb->data_len but leaves skb->len containing the old fragment contribution. After a fragment shrink, this makes skb_h…
Summary: CVE record, as of .
- CISA has not added CVE-2026-74612 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 22 Aug 2026.
- The CVE record carries a CVSS v3.1 base score of 10.0 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.5% (percentile 42.1), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation none, automatable yes, technical impact total.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
veth: fix skb length accounting after XDP frag adjustment
In the Linux kernel, the following vulnerability has been resolved: veth: fix skb length accounting after XDP frag adjustment veth exposes non-linear skb fragments through an xdp_buff. If an XDP program adjusts the fragment area, veth_xdp_rcv_skb() copies xdp_frags_size back to skb->data_len but leaves skb->len containing the old fragment contribution. After a fragment shrink, this makes skb_headlen() larger than the actual linear area. In the reproduced UDP receive path, __skb_datagram_iter() copied 1024 bytes past the actual linear tail to userspace, starting at struct skb_shared_info. The copied bytes included the affected skb's nr_frags, xdp_frags_size, and a kernel pointer from skb_shinfo(skb)->frags[0]. Real packet data was displaced by the same amount and truncated at the end. Subtract the old data_len before replacing it and add the new data_len afterwards, keeping skb->len and skb->data_len synchronized. Additionally, bpf_xdp_pull_data() can advance data_end while leaving frags present. The skb is then still non-linear, so the old __skb_put(skb, off) triggers SKB_LINEAR_ASSERT(). Use skb_set_tail_pointer() and update skb->len explicitly instead, following bpf_prog_run_generic_xdp(). Unlike __skb_put(), skb_set_tail_pointer() does not require a linear skb. A 60000-byte UDP datagram on a veth pair with MTU 64000 was shortened by 1024 bytes from its fragment area. Before the fix, all 10 runs produced corrupted payloads. After the fix, all 10 runs matched the expected payload exactly. A forced-tailroom reproducer also exercises bpf_xdp_pull_data() with frags still present; the old code triggers SKB_LINEAR_ASSERT(), while this fix passes 10/10 runs.
Source: CVE List, as of . About the data.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
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