CVE-2026-53091
HIGHCVE-2026-53091 is a high-severity (CVSS 8.4) CWE-131 vulnerability in Kernel. O3 Security confirms whether CVE-2026-53091 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
net: pull headers in qdisc_pkt_len_segs_init()
Real-World Exposure
KernelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.
Description
In the Linux kernel, the following vulnerability has been resolved:
net: pull headers in qdisc_pkt_len_segs_init()
Most ndo_start_xmit() methods expects headers of gso packets to be already in skb->head.
net/core/tso.c users are particularly at risk, because tso_build_hdr() does a memcpy(hdr, skb->data, hdr_len);
qdisc_pkt_len_segs_init() already does a dissection of gso packets.
Use pskb_may_pull() instead of skb_header_pointer() to make sure drivers do not have to reimplement this.
Some malicious packets could be fed, detect them so that we can drop them sooner with a new SKB_DROP_REASON_SKB_BAD_GSO drop_reason.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐧Linux | Kernel | ≥ 3.16.0&&< 7.0.10 | 7.0.10 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Kernel to 7.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-53091 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-53091 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-53091. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-53091 in your dependencies?
O3 detects CVE-2026-53091 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.