high CVSS 7.8 EPSS <0.1%

CVE-2022-49541·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: cifs: fix potential double free during failed mount RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=2088799

Severity
high
Software
Kernel
Fixed in
5.18.3
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-2022-49541 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: 5.18

Until: 5.18.3

Fixed in: 5.18.3

How to fix this CVE

Update your Linux kernel to version 5.18.3 or later to resolve a critical double-free memory corruption vulnerability in CIFS mount handling. This flaw can occur when a mount operation fails, leading to improper memory deallocation that may allow privilege escalation. Apply the latest stable kernel patches immediately across all affected systems.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check current kernel version: uname -r (should be 5.18.3 or higher)
  2. Verify CIFS module is loaded: lsmod | grep cifs
  3. Review CIFS mount configurations in /etc/fstab and /proc/mounts for active mounts
  4. Confirm patch application by checking kernel build date: cat /proc/version and comparing to release notes for 5.18.3

FAQ

What is CVE-2022-49541?

This vulnerability is a double-free memory corruption flaw in the Linux kernel's CIFS (Common Internet File System) subsystem that occurs during failed mount operations. When a mount attempt fails, improper cleanup logic may deallocate the same memory region twice, leading to heap corruption.

Is CVE-2022-49541 being actively exploited?

No, this CVE is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are currently available, though the high CVSS score (7.8) indicates significant privilege escalation potential.

What versions of Kernel are affected by CVE-2022-49541?

Linux kernel versions 5.18 through 5.18.2 are vulnerable. The fix was integrated in kernel 5.18.3 and all subsequent releases.

How do I check if my server is vulnerable to CVE-2022-49541?

Run 'uname -r' to display your kernel version. If it shows 5.18.0 through 5.18.2, your system is vulnerable. Check if CIFS is in use with 'grep cifs /proc/mounts'.

Does Defensia detect CVE-2022-49541?

Yes — Defensia's CVE advisory scanner compares installed kernel versions against the NVD database. If kernel 5.18.0-5.18.2 is detected on a monitored server, CVE-2022-49541 will appear in your dashboard with remediation steps.

Related Kernel CVEs

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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.
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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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