CVE-2026-90049: Linux Vulnerability (CVSS 9.3)

Description

In the Linux kernel, the following vulnerability has been resolved: net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy() skb_zerocopy() copies frags from @from into @to. On an skb_orphan_frags() failure it calls skb_tx_error(@from), a destructive operation on the source skb the copy helper does not own. That completes @from's zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, including the SKBFL_SHARED_FRAG page-ownership marker. Both callers already report the failure on their own drop path. nfnetlink_queue does it at nla_put_failure, and Open vSwitch does it in the flow-miss drop arm of ovs_dp_process_packet(), so nothing is lost by dropping it here. On Open vSwitch's OVS_ACTION_ATTR_USERSPACE path the skb is not freed on this error: do_execute_actions() ignores output_userspace()'s return value and, unless the upcall was the last action, keeps forwarding the same skb through the flow's remaining actions. The uarg is completed while that skb is still in flight, telling the producer its buffers are free, and SKBFL_SHARED_FRAG is cleared on an skb the rest of the stack still handles. That flag is what makes esp_input() call skb_cow_data() instead of decrypting in place, so a later local ESP delivery can decrypt over frags the skb does not own privately. Leave error reporting to the callers.

Metrics

CVSS 3.1

9.3/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 36d5fe6a000790f56039afe26834265db0a3ad4c, < 849bdb83123760a865bcb2970127f4c0b9423ba3; >= 36d5fe6a000790f56039afe26834265db0a3ad4c, < fb10e0e9b220a2eed08931a60dbaad9a2370c908; >= 36d5fe6a000790f56039afe26834265db0a3ad4c, < 767ec2a65cc022d303b0c9c12811e7db22057341; >= 36d5fe6a000790f56039afe26834265db0a3ad4c, < 8069643ae64dfdf634b6c78c7f622e5323031436; >= 36d5fe6a000790f56039afe26834265db0a3ad4c, < 04dd250a78e268af3e7124beb1dc10ec1dd88d60; >= 36d5fe6a000790f56039afe26834265db0a3ad4c, < a13b1e80e5015cd732440b475c0ef443dc4a2157; >= 36d5fe6a000790f56039afe26834265db0a3ad4c, < bab5a851e44a3601d31f2aa8043f385bb50ac5d9; >= 36d5fe6a000790f56039afe26834265db0a3ad4c, < 8ece906150128d5ec2462aabcc978c568433eca4; c5f0c0e7525443add533495e93ba8de6feab2396; 1674b4bf3eea3cac51b70778e89f8025f7cfe695; >= 3.10.51, < 3.11; >= 3.12.40, < 3.13
Linux	Linux	3.14

References

Timeline

Published: Sep 16, 2026
Last Modified: Sep 16, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-90049?

In the Linux kernel, the following vulnerability has been resolved: net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy() skb_zerocopy() copies frags from @from into @to. On an skb_orphan_frags() failure it calls skb_tx_error(@from), a destructive operation on the source skb the copy helper does not own. That completes @from's zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, including the SKBFL_SHARED_FRAG page-ownership marker. Both callers already report the failure on their own drop path. nfnetlink_queue does it at nla_put_failure, and Open vSwitch does it in the flow-miss drop arm of ovs_dp_process_packet(), so nothing is lost by dropping it here. On Open vSwitch's OVS_ACTION_ATTR_USERSPACE path the skb is not freed on this error: do_execute_actions() ignores output_userspace()'s return value and, unless the upcall was the last action, keeps forwarding the same skb through the flow's remaining actions. The uarg is completed while that skb is still in flight, telling the producer its buffers are free, and SKBFL_SHARED_FRAG is cleared on an skb the rest of the stack still handles. That flag is what makes esp_input() call skb_cow_data() instead of decrypting in place, so a later local ESP delivery can decrypt over frags the skb does not own privately. Leave error reporting to the callers.

How severe is CVE-2026-90049?

CVE-2026-90049 has a CVSS score of 9.3/10 (CRITICAL severity).

How do I fix CVE-2026-90049?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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