CVE-2026-52981

Description

In the Linux kernel, the following vulnerability has been resolved: neigh: let neigh_xmit take skb ownership neigh_xmit always releases the skb, except when no neighbour table is found. But even the first added user of neigh_xmit (mpls) relied on neigh_xmit to release the skb (or queue it for tx). sashiko reported: If neigh_xmit() is called with an uninitialized neighbor table (for example, NEIGH_ND_TABLE when IPv6 is disabled), it returns -EAFNOSUPPORT and bypasses its internal out_kfree_skb error path. Because the return value of neigh_xmit() is ignored here, does this leak the SKB? Assume full ownership and remove the last code path that doesn't xmit or free skb.

CVSS v3.1 Score

7.5

HIGH

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

EPSS — Exploit Prediction

0.0054

Probability of exploitation

0.41%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/0084712e0bee204b284510cdb63182fd5a30c2b7 https://git.kernel.org/stable/c/4438113be604ee67a7bf4f81da6e1cca41332ce4 https://git.kernel.org/stable/c/445e45a2c3a078316a62d2d331a570cf34ef5079 https://git.kernel.org/stable/c/63063ba60d2dc334e34f1e3f9271d7f3f6f30307 https://git.kernel.org/stable/c/8a89054a1ec0767aec25ed2bbac933da6ba3cf5a https://git.kernel.org/stable/c/9247d59ca15bf60a57dca08103f055d8a4340877

Frequently Asked Questions

What is CVE-2026-52981? +

In the Linux kernel, the following vulnerability has been resolved: neigh: let neigh_xmit take skb ownership neigh_xmit always releases the skb, except when no neighbour table is found. But even the first added user of neigh_xmit (mpls) relied on neigh_xmit to release the skb (or queue it for tx). sashiko reported: If neigh_xmit() is called with an uninitialized neighbor table (for example, NEIGH_ND_TABLE when IPv6 is disabled), it returns -EAFNOSUPPORT and bypasses its internal out_kfree_skb error path. Because the return value of neigh_xmit() is ignored here, does this leak the SKB? Assume full ownership and remove the last code path that doesn't xmit or free skb. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-52981? +

CVE-2026-52981 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0054, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-52981? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.