CVE-2026-98555 (CVSS 7.5)

Description

In the Linux kernel, the following vulnerability has been resolved: llc: fix skb UAF and leaks on llc_mac_hdr_init() failure In llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(), if llc_mac_hdr_init() fails, kfree_skb(skb) is called instead of kfree_skb(nskb). This leaks the newly allocated nskb, reads from the freed skb via LLC_I_GET_NR(pdu), and double-frees skb when llc_conn_state_process() drops its reference. In llc_sap_action_send_xid_r() and llc_sap_action_send_test_r(), nskb is leaked if llc_mac_hdr_init() returns an error. Free nskb in all three error paths.

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CVSS v3.1 Score

7.5

HIGH

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

EPSS — Exploit Prediction

0.0031

Probability of exploitation

0.24%

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/060f827aa3dc47939ee306da715cd6700d129616 https://git.kernel.org/stable/c/41dcae82bece9f106b4dff0ee777bba8d157c8a8 https://git.kernel.org/stable/c/72f9dd522f8d6c5a00be9695c7bb74631eb5069e https://git.kernel.org/stable/c/8b855b645841b5a04e20339a22bb6d593c9b790d https://git.kernel.org/stable/c/b859ba18b5a1067f71db5618c6a4a70d55fa308b https://git.kernel.org/stable/c/cb3528ad8bb46fa6252f5d14ced7febddc18515d https://git.kernel.org/stable/c/d360b31f1a3666579422872aa7d1a751e20b76f9 https://git.kernel.org/stable/c/fec0fe6838a7f45175667701fb51abb23a6ffb1e

Frequently Asked Questions

What is CVE-2026-98555? +

In the Linux kernel, the following vulnerability has been resolved: llc: fix skb UAF and leaks on llc_mac_hdr_init() failure In llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(), if llc_mac_hdr_init() fails, kfree_skb(skb) is called instead of kfree_skb(nskb). This leaks the newly allocated nskb, reads from the freed skb via LLC_I_GET_NR(pdu), and double-frees skb when llc_conn_state_process() drops its reference. In llc_sap_action_send_xid_r() and llc_sap_action_send_test_r(), nskb is leaked if llc_mac_hdr_init() returns an error. Free nskb in all three error paths. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-98555? +

CVE-2026-98555 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 0.0031, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-98555? +

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.

CVE-2026-98555