CVE-2025-39880: Linux Kernel vulnerability (CVSS 9.8)

Description

In the Linux kernel, the following vulnerability has been resolved: libceph: fix invalid accesses to ceph_connection_v1_info There is a place where generic code in messenger.c is reading and another place where it is writing to con->v1 union member without checking that the union member is active (i.e. msgr1 is in use). On 64-bit systems, con->v1.auth_retry overlaps with con->v2.out_iter, so such a read is almost guaranteed to return a bogus value instead of 0 when msgr2 is in use. This ends up being fairly benign because the side effect is just the invalidation of the authorizer and successive fetching of new tickets. con->v1.connect_seq overlaps with con->v2.conn_bufs and the fact that it's being written to can cause more serious consequences, but luckily it's not something that happens often.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Debian Linux11.0

Linux Kernel≥ 5.11 < 5.15.194 · ≥ 5.16 < 6.1.153 · ≥ 6.13 < 6.16.8 · ≥ 6.2 < 6.6.107

Remediation

Fixed in

Linux Kernel≥ 5.15.194

Patch & vendor advisories

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2025-39880 being actively exploited?

CVE-2025-39880 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.32%.

How severe is CVE-2025-39880?

CVE-2025-39880 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.32% probability of exploitation.

Which products are affected by CVE-2025-39880?

Affected products include Debian Linux, Linux Kernel.

How do I fix CVE-2025-39880?

Upgrade affected software to a fixed version, for example Linux Kernel 5.15.194 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-39880 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation works Book a demo