CVE-2023-54039

CVE-2023-54039 is a security vulnerability that is still awaiting full analysis and scoring. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: can: j1939: j1939_tp_tx_dat_new(): fix out-of-bounds memory access In the j1939_tp_tx_dat_new() function, an out-of-bounds memory access could occur during the memcpy() operation if the size of skb->cb is larger than the size of struct j1939_sk_buff_cb. This is because the memcpy() operation uses the size of skb->cb, leading to a read beyond the struct j1939_sk_buff_cb. Updated the memcpy() operation to use the size of struct j1939_sk_buff_cb instead of the size of skb->cb. This ensures that the memcpy() operation only reads the memory within the bounds of struct j1939_sk_buff_cb, preventing out-of-bounds memory access. Additionally, add a BUILD_BUG_ON() to check that the size of skb->cb is greater than or equal to the size of struct j1939_sk_buff_cb. This ensures that the skb->cb buffer is large enough to hold the j1939_sk_buff_cb structure. [mkl: rephrase commit message]

Frequently asked questions

What is CVE-2023-54039?
In the Linux kernel, the following vulnerability has been resolved: can: j1939: j1939_tp_tx_dat_new(): fix out-of-bounds memory access In the j1939_tp_tx_dat_new() function, an out-of-bounds memory access could occur during the memcpy() operation if the size of skb->cb is larger than the size of struct j1939_sk_buff_cb. This is because the memcpy() operation uses the size of skb->cb, leading to a read beyond the struct j1939_sk_buff_cb. Updated the memcpy() operation to use the size of struct j1939_sk_buff_cb instead of the size of skb->cb. This ensures that the memcpy() operation only reads the memory within the bounds of struct j1939_sk_buff_cb, preventing out-of-bounds memory access. Additionally, add a BUILD_BUG_ON() to check that the size of skb->cb is greater than or equal to the size of struct j1939_sk_buff_cb. This ensures that the skb->cb buffer is large enough to hold the j1939_sk_buff_cb structure. [mkl: rephrase commit message]
Is CVE-2023-54039 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2023-54039?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2023-54039 have an EU (EUVD) identifier?
Yes. CVE-2023-54039 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-205114.
When was CVE-2023-54039 published?
CVE-2023-54039 was published on 2025-12-24 and last updated on 2026-06-17.

References