CVE-2026-68158 libceph: Fix multiplication overflow in decode_new_up_state_weight()
A malicious Ceph OSD map message can trigger an integer overflow leading to out-of-bounds memory access, potentially causing crashes or information disclosure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68158?
CVE-2026-68158 is a critical vulnerability in Linux, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
libceph: Fix multiplication overflow in decode_new_up_state_weight()
If a message of type CEPH_MSG_OSD_MAP contains a (maliciously) corrupted osdmap, out-of-bounds memory accesses may occur in decode_new_up_state_weight(). This happens because the bounds check for the new_state part is based on calculating its length depending on a len value read from the incoming message. This calculation may overflow leading to an incorrect bounds check. Subsequently, out-of-bounds reads may occur when decoding this part.
This patch switches the multiplication to use check_mul_overflow() to abort processing the osdmap if an overflow occurred. Therefore, osdmaps/messages containing large values for len that result in a multiplication overflow are treated as invalid.
[ idryomov: rename new_state_len -> new_state_item_size, formatting ]
Weakness: CWE-190
Which versions are affected by CVE-2026-68158?
How do I fix CVE-2026-68158?
Apply the vendor's patch.
Is CVE-2026-68158 being exploited?
There is no known exploitation of CVE-2026-68158 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68158, DEBIAN-CVE-2026-68158, GHSA-jg8v-h49p-mvhw, UBUNTU-CVE-2026-68158.