CVE-2026-63924High· 7.0▾ TwilightA flaw was found in the Linux kernel's handling of IPv6 extended headers. Specifically, the `ipv6_hop_jumbo()` function, which processes jumbo payloads, can modify internal packet buffer (skb) pointers. However, the network header (nh) poi…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 38.5 · likelihood 0.1 · exploitation 0
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Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the vendor's CSAF advisory record, not NVD.
Exploit-prediction probability, daily snapshots since Oct 16.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via CSAF
0.7%
9.8 → 7
critical → high
7 → 9.8
high → critical
Last analysed / modified upstream
9.8 → 7
critical → high
A flaw was found in the Linux kernel's handling of IPv6 extended headers. Specifically, the ipv6_hop_jumbo() function, which processes jumbo payloads, can modify internal packet buffer (skb) pointers. However, the network header (nh) pointer is not recomputed after these modifications. This oversight could lead to incorrect data processing, potentially causing system instability or a denial of service (DoS) due to malformed packets.
kernel: ipv6: exthdrs: refresh nh pointer after ipv6_hop_jumbo() — rated Important by Red Hat. Released 2026-07-19, updated 2026-10-26.
Affected:
Fixed:
No fix planned:
For details on how to apply this update, which includes the changes described in this advisory, refer to:
https://access.redhat.com/articles/11258
The system must be rebooted for this update to take effect.
Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.
Because of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:76738 For details on how to apply this update, which includes the changes described in this advisory, refer to:
https://access.redhat.com/articles/11258
The system must be rebooted for this update to take effect.
Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.
Because of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:83796 For details on how to apply this update, which includes the changes described in this advisory, refer to:
https://access.redhat.com/articles/11258
The system must be rebooted for this update to take effect.
Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.
Because of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:83707
Workarounds / mitigations:
Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-63922High· 7.0kernel: ipv6: exthdrs: refresh nh after handling HAO option (CVE-2026-63922)
CVE-2026-80792High· 7.0kernel: ipv6: fix use-after-free in ip6_finish_output2() (CVE-2026-80792)
CVE-2026-74746Critical· 9.8In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: publish GC-visible tuple last nf_flow_table_iterate() only treats original-direction tuple nodes as owning entries
CVE-2026-63984High· 7.0kernel: ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress() (CVE-2026-63984)
CVE-2026-63920High· 7.0kernel: ipv6: validate extension header length before copying to cmsg (CVE-2026-63920)
CVE-2026-68121High· 7.3kernel: pppoe: reload header pointer after dev_hard_header() (CVE-2026-68121)