high CVSS 7.8 EPSS <0.1%

CVE-2024-36978·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: net: sched: sch_multiq: fix possible OOB write in multiq_tune() q->bands will be assigned to qopt->bands to execute subsequent code logic after kmalloc. So the old q->bands should not be used in kmalloc. Otherwise, an out-of-bounds write will occur.

Severity
high
Software
Kernel
Fixed in
6.9.6
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 9% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Read the two together. CVE-2024-36978 scores 7.8 on CVSS, so a successful attack would be serious — but at <0.1%, almost nobody is currently attempting it. That is a different situation from a flaw under mass exploitation, and it is usually the difference between patching on your next maintenance window and patching tonight.

Affected versions

From: 6.7

Until: 6.9.6

Fixed in: 6.9.6

How to fix this CVE

Update your Linux kernel to version 6.9.6 or later to resolve this memory allocation vulnerability in the multiq queuing discipline. The issue stems from incorrect buffer sizing during queue configuration changes, which could lead to kernel memory corruption. Applying this patch immediately is recommended for production systems, especially those using traffic shaping or QoS features.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Run 'uname -r' to check your current kernel version and compare against 6.9.6 or later
  2. Verify if multiq queuing discipline is active with 'tc qdisc show' and look for 'multiq' entries
  3. Search system logs for memory corruption indicators: 'sudo grep -i 'kernel.*oob\|out of bounds\|memory corruption' /var/log/kern.log'
  4. Confirm the patch is applied by checking '/proc/version' shows kernel 6.9.6+ or by verifying git commit hashes in kernel source

FAQ

What is CVE-2024-36978?

This vulnerability is a buffer overflow in the Linux kernel's multiq network scheduler that occurs when reconfiguring queue bands. An attacker with local access could trigger memory corruption by modifying traffic control settings, potentially gaining elevated privileges.

Is CVE-2024-36978 being actively exploited?

No, this vulnerability is not currently listed in CISA's Known Exploited Vulnerabilities (KEV) catalog and has no public exploits available. However, it should still be patched as a high-severity kernel flaw.

What versions of Kernel are affected by CVE-2024-36978?

Linux kernel versions 6.7 through 6.9.5 are vulnerable. Version 6.9.6 and all subsequent releases contain the fix.

How do I check if my server is vulnerable to CVE-2024-36978?

Run 'uname -r' and compare the output against 6.9.6. If your version is between 6.7 and 6.9.5, your system is vulnerable. Additionally, check if multiq qdisc is in use with 'tc qdisc show | grep multiq'.

Does Defensia detect CVE-2024-36978?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2024-36978 will appear in your dashboard with remediation steps.

Related Kernel CVEs

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CVE-2026-53221CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup() In vti6_tnl_lookup(), when an exact match for a tunnel fails, the code falls back to searching for wildcard tunnels: - Tunnels matching the packet's local address, with any remote address wildcard remote). - Tunnels matching the packet's remote address, with any local address (wildcard local). However, vti6 stores all these different types of tunnels in the same hash table (ip6n->tnls_r_l) prone to hash collisions. The bug is that the fallback search loops in vti6_tnl_lookup() were missing checks to ensure that the candidate tunnel actually has a wildcard address.
CVE-2026-53151CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix the ACK parser to extract the SACK table for parsing Fix modification of the received skbuff in rxrpc_input_soft_acks() and a potential incorrect access of the buffer in a fragmented UDP packet (the packet would probably have to be deliberately pre-generated as fragmented) when AF_RXRPC tries to extract the contents of the SACK table by copying out the contents of the SACK table into a buffer before attempting to parse AF_RXRPC assumes that it can just call skb_condense() and then validly access the SACK table from skb->data and that it will be a flat buffer - but skb_condense() can silently fail to do anything under some circumstances. Note that whilst rxrpc_input_soft_acks() should be able to parse extended ACKs, the rest of AF_RXRPC doesn't currently support that. Further, there's then no need to call skb_condense() in rxrpc_input_ack(), so don't.
CVE-2026-53088CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: net: bcmgenet: fix off-by-one in bcmgenet_put_txcb The write_ptr points to the next open tx_cb. We want to return the tx_cb that gets rewinded, so we must rewind the pointer first then return the tx_cb that it points to. That way the txcb can be correctly cleaned up.
CVE-2026-53228CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ipv6: sit: reload inner IPv6 header after GSO offloads ipip6_tunnel_xmit() caches the inner IPv6 header pointer at function entry and continues using it after iptunnel_handle_offloads(). For GSO skbs, iptunnel_handle_offloads() calls skb_header_unclone(). When the skb header is cloned, skb_header_unclone() can call pskb_expand_head(), which may move the skb head. The pskb_expand_head() contract requires pointers into the skb header to be reloaded after the call. If the later skb_realloc_headroom() branch is not taken, SIT uses the stale iph6 pointer to read the inner hop limit and DS field. That can read from a freed skb head after the old head's remaining clone is released. Reload iph6 after the offload helper succeeds and before subsequent reads from the inner IPv6 header. Keep the existing reload after skb_realloc_headroom(), since that branch can also replace the skb.

References

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