NVD / CVE Program· CNA Linux

CVE-2026-43406: libceph: prevent potential out-of-bounds reads in process_message_header()

CriticalCVSS 9.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 36/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.61% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: Linux Linux 035867ae6f18df0aeedb2a57a5b74091bd4e3fe8, 50156622eb0888e62541d715a98584480a1bc7cb, 69fb5d91bba44ecf7eb80530b85fa4fb028921d5.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 035867ae6f18df0aeedb2a57a5b74091bd4e3fe8, 50156622eb0888e62541d715a98584480a1bc7cb, 69fb5d91bba44ecf7eb80530b85fa4fb028921d5 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: libceph: prevent potential out-of-bounds reads in process_message_header() If the message frame is (maliciously) corrupted in a way that the length of the control segment ends up being less than the size of the message header or a different frame is made to look like a message frame, out-of-bounds reads may ensue in process_message_header(). Perform an explicit bounds check before decoding the message header.

BDU:2026-12088

Published: May 8, 2026
Updated: Nov 11, 2026
EPSS: 0.6% · 49th percentile
CWE: CWE-125

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 36 / 40 · 9.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 9.1; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 5.11affected
- cd1a677cad994021b19665ed476aea63f5d54f31 and later · before 76ccf21a12c5f6d6790bc32c7da82446d877b2f4affected · git
- cd1a677cad994021b19665ed476aea63f5d54f31 and later · before 75582aaa580c11aed4c7731cad6b068b700e7efbaffected · git
- cd1a677cad994021b19665ed476aea63f5d54f31 and later · before 50156622eb0888e62541d715a98584480a1bc7cbaffected · git
- cd1a677cad994021b19665ed476aea63f5d54f31 and later · before dbd857a9e1e33ea71eaf3e211877027e533770d1affected · git
- cd1a677cad994021b19665ed476aea63f5d54f31 and later · before 69fe5af33fa3806f398d21c081d73c66e5523bc2affected · git
- cd1a677cad994021b19665ed476aea63f5d54f31 and later · before 035867ae6f18df0aeedb2a57a5b74091bd4e3fe8affected · git
- cd1a677cad994021b19665ed476aea63f5d54f31 and later · before 69fb5d91bba44ecf7eb80530b85fa4fb028921d5affected · git
- before 5.11not affected · semver
- 5.15.203 and later · up to and including 5.15.*not affected · semver

Affected versions · NVD (7)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel5.11 and later · before 5.15.203
linux linux kernel5.16 and later · before 6.1.167
linux linux kernel6.2 and later · before 6.6.130
linux linux kernel6.7 and later · before 6.12.78
linux linux kernel6.13 and later · before 6.18.19
linux linux kernel6.19 and later · before 6.19.9
linux linux kernel7.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.170-1	6.1.170-1
Debian:13	linux	before 6.12.85-1	6.12.85-1
Debian:14	linux	before 6.19.10-1	6.19.10-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
90Now
CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2026-43404May 8, 2026 · mm: Fix a hmm_range_fault() livelock / starvation problem
22Monitor
← EarlierCVE-2026-43405May 8, 2026 · libceph: Use u32 for non-negative values in ceph_monmap_decode()
30Monitor
Later →CVE-2026-43407May 8, 2026 · libceph: Fix potential out-of-bounds access in ceph_handle_auth_reply()
36Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	035867ae6f18df0aeedb2a57a5b74091bd4e3fe8	Vendor (CNA)
Linux Linux	50156622eb0888e62541d715a98584480a1bc7cb	Vendor (CNA)
Linux Linux	69fb5d91bba44ecf7eb80530b85fa4fb028921d5	Vendor (CNA)
Linux Linux	69fe5af33fa3806f398d21c081d73c66e5523bc2	Vendor (CNA)
Linux Linux	75582aaa580c11aed4c7731cad6b068b700e7efb	Vendor (CNA)
Linux Linux	76ccf21a12c5f6d6790bc32c7da82446d877b2f4	Vendor (CNA)
Linux Linux	dbd857a9e1e33ea71eaf3e211877027e533770d1	Vendor (CNA)
debian:linux	6.1.170-1 · Debian:12	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.