CyberSecBulletin
CVE-2026-68127NVD status: Received

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-68127 is a critical-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions e451a904606c571f731ef7a06b3398619dce5300, 1eadcb43893b897ade85ac5bf5c618054bc3c655, ba353caafb06ccee57b78d3254e3cebf1dea4a93 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.54% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to e451a904606c571f731ef7a06b3398619dce5300 or 1eadcb43893b897ade85ac5bf5c618054bc3c655 or ba353caafb06ccee57b78d3254e3cebf1dea4a93 or 896a9512d0d83c2a4b357e5585b7b62a8e3f95c1, whichever matches your release line, or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux33f11d16142b06588eedfc1dd8cf93790979a712 up to, but not including, e451a904606c571f731ef7a06b3398619dce5300; 33f11d16142b06588eedfc1dd8cf93790979a712 up to, but not including, 1eadcb43893b897ade85ac5bf5c618054bc3c655; 33f11d16142b06588eedfc1dd8cf93790979a712 up to, but not including, ba353caafb06ccee57b78d3254e3cebf1dea4a93; 33f11d16142b06588eedfc1dd8cf93790979a712 up to, but not including, 896a9512d0d83c2a4b357e5585b7b62a8e3f95c1; 33f11d16142b06588eedfc1dd8cf93790979a712 up to, but not including, 7097a0280b178237265681be66d1bef11d15894b; 33f11d16142b06588eedfc1dd8cf93790979a712 up to, but not including, 472aba2603ca74c4f7722cb0c0296942b0776b8d; 33f11d16142b06588eedfc1dd8cf93790979a712 up to, but not including, c6a13ae00dab3a1a8c7cf2f843f0fc9e8d4b0ccc; 33f11d16142b06588eedfc1dd8cf93790979a712 up to, but not including, 92d3817649df2b0b6a008a686c8275c88d7ef594; and 1 more rangese451a904606c571f731ef7a06b3398619dce5300, 1eadcb43893b897ade85ac5bf5c618054bc3c655, ba353caafb06ccee57b78d3254e3cebf1dea4a93, 896a9512d0d83c2a4b357e5585b7b62a8e3f95c1, 7097a0280b178237265681be66d1bef11d15894b, 472aba2603ca74c4f7722cb0c0296942b0776b8d

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: ila: reload IPv6 header after pskb_may_pull in checksum adjust ila_csum_adjust_transport() caches ip6h = ipv6_hdr(skb) before calling pskb_may_pull(). On a non-linear skb whose transport header sits in a page fragment, pskb_may_pull() can call __pskb_pull_tail() / pskb_expand_head() and free the old skb head, leaving ip6h dangling; the following get_csum_diff(ip6h, p) then reads freed memory. ila_update_ipv6_locator() uses ip6h (and the iaddr derived from it) again after the csum-adjust call and additionally writes the new locator through that pointer. Impact: a remote IPv6 packet routed through a configured ILA csum-adjust-transport route or receive-side mapping triggers a slab-use-after-free in ila_update_ipv6_locator() (KASAN). The route or mapping requires CAP_NET_ADMIN to configure, but trigger packets are unauthenticated once it exists. Reload ip6h after each pskb_may_pull() in ila_csum_adjust_transport() before the csum-diff read. In ila_update_ipv6_locator() only the ILA_CSUM_ADJUST_TRANSPORT case pulls the skb, so reload ip6h and iaddr in that case alone before the destination-address write; the neutral-map modes never pull and keep their cached pointers.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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