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CVE-2026-74659

Unknown

Last modified

CVE-2026-74659 is a vulnerability of currently unknown severity. In the Linux kernel, the following vulnerability has been resolved: net: bridge: mrp: fix uninitialised bytes on the wire br_mrp_alloc_test_skb() builds MRP test frames on an skb from dev_alloc_skb(), which does not clear the linear data area. On the MRA ring-role branch the sub-option TLV header is appended with sub_tlv = skb_put(skb, sizeof(*sub_tlv)); sub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR; so sub_tlv->length is never written, and the two trailing alignment bytes are appended with a bare skb_put() that does not clear them either.

Description

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mrp: fix uninitialised bytes on the wire br_mrp_alloc_test_skb() builds MRP test frames on an skb from dev_alloc_skb(), which does not clear the linear data area. On the MRA ring-role branch the sub-option TLV header is appended with sub_tlv = skb_put(skb, sizeof(*sub_tlv)); sub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR; so sub_tlv->length is never written, and the two trailing alignment bytes are appended with a bare skb_put() that does not clear them either. The neighbouring oui and sub_opt regions are explicitly zeroed, so three uninitialised bytes are left in every MRA MRP_Test frame that goes out. Put the sub-option TLV header and the alignment padding in a single skb_put_zero(), which clears both. The AUTO_MGR sub-TLV carries no payload, so the zeroed length field is already the value it should have.

Affected Software

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

VendorProductVersions
LinuxLinux>= f7458934b0791c39a001e4d902fc3bf697b439b5, < 014c062d23c63ec77ef2cf17a0d9363c7441cc94; >= f7458934b0791c39a001e4d902fc3bf697b439b5, < 7ebc23ff03668042e0b0e4034bb1518d36198d9e; >= f7458934b0791c39a001e4d902fc3bf697b439b5, < 06d58b8d2f053ced82e01efaeb6e7c82891eed58; >= f7458934b0791c39a001e4d902fc3bf697b439b5, < a5e385eeb2d6dbbbdebfa050e67c34734ae12693; >= f7458934b0791c39a001e4d902fc3bf697b439b5, < 5912cf1822fbe53ae275c147868740eb384a5d3e; >= f7458934b0791c39a001e4d902fc3bf697b439b5, < e08665218040f8e312abe40f74543186f3c2c941; >= f7458934b0791c39a001e4d902fc3bf697b439b5, < 63488dba65ef91373ef616575b32eb0eb21459f4
LinuxLinux5.14

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-74659?
In the Linux kernel, the following vulnerability has been resolved: net: bridge: mrp: fix uninitialised bytes on the wire br_mrp_alloc_test_skb() builds MRP test frames on an skb from dev_alloc_skb(), which does not clear the linear data area. On the MRA ring-role branch the sub-option TLV header is appended with sub_tlv = skb_put(skb, sizeof(*sub_tlv)); sub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR; so sub_tlv->length is never written, and the two trailing alignment bytes are appended with a bare skb_put() that does not clear them either. The neighbouring oui and sub_opt regions are explicitly zeroed, so three uninitialised bytes are left in every MRA MRP_Test frame that goes out. Put the sub-option TLV header and the alignment padding in a single skb_put_zero(), which clears both. The AUTO_MGR sub-TLV carries no payload, so the zeroed length field is already the value it should have.
How severe is CVE-2026-74659?
Severity scoring for CVE-2026-74659 is pending analysis.
How do I fix CVE-2026-74659?
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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Source: NVD / NIST