CVE-2026-68155: libceph: Reject monmaps advertising zero monitors
Noroxi assessment
Priority: Monitor (action score 30/100)
- 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: 0.69% (FIRST EPSS); higher than 53.2% of all records.
- 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 0591a15815b498be628a937146e44487d599ba33, 3b249546f59c3d6d3592c10657f82bc3f1faa07c, 40480eee361ed9676b3f844d532ac28b47251634.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 0591a15815b498be628a937146e44487d599ba33, 3b249546f59c3d6d3592c10657f82bc3f1faa07c, 40480eee361ed9676b3f844d532ac28b47251634 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: Reject monmaps advertising zero monitors A message of type CEPH_MSG_MON_MAP contains a monmap that is sent from a monitor to the client. This monmap contains information about the existing monitors in the cluster. Currently, a monmap indicating that there are zero monitors in the cluster is treated as valid. However, it is impossible to have zero monitors in the cluster and still receive a valid monmap from a monitor. Therefore, such a monmap must be corrupted and should be treated as invalid. Furthermore, a monmap with a monitor count of zero can subsequently crash the client when attempting to open a session with a monitor in __open_session(). This happens because the "BUG_ON(monc->monmap->num_mon < 1)" assertion in pick_new_mon() is triggered. This patch extends a check in ceph_monmap_decode() to also reject arriving mon_maps with num_mon == 0 rather than only with num_mon > CEPH_MAX_MON. [ idryomov: drop "log output for unusual values of num_mon" part ]
- Published
- Aug 10, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.6% · 53th percentile
- CWE
- CWE-20
Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 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
- 7.5
- 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
If any of these changes, we'll tell you in the daily email digest.
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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.
We use this product, ask for helpAffected 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.
—
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
- 2.6.34affected
- ba75bb98cfb93b62c54af25bf67ff90857264bbe and later · before ba5f0015bfd376d764163045a61c17be75f44daeaffected · git
- ba75bb98cfb93b62c54af25bf67ff90857264bbe and later · before caf082ef8609a6ac26159ce115f55ab7d00231a3affected · git
- ba75bb98cfb93b62c54af25bf67ff90857264bbe and later · before e3ccd4ecab09b22f507f49cb7ed9990c7158ceabaffected · git
- ba75bb98cfb93b62c54af25bf67ff90857264bbe and later · before 0591a15815b498be628a937146e44487d599ba33affected · git
- ba75bb98cfb93b62c54af25bf67ff90857264bbe and later · before cd0d41bc569632eaaeccde9d2a6bc919ec00c407affected · git
- ba75bb98cfb93b62c54af25bf67ff90857264bbe and later · before e67e8b694872c9bc66996040f9de9242f6236ed9affected · git
- ba75bb98cfb93b62c54af25bf67ff90857264bbe and later · before 3b249546f59c3d6d3592c10657f82bc3f1faa07caffected · git
- ba75bb98cfb93b62c54af25bf67ff90857264bbe and later · before 40480eee361ed9676b3f844d532ac28b47251634affected · git
- before 2.6.34not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | kernel-64k-debug-devel | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-devel-matched | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-64k-devel | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-64k-devel-matched | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-cross-headers | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-debug | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-debug-core | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-debug-devel | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-debug-devel-matched | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-debug-modules | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-debug-modules-core | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-debug-modules-extra | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-debug-uki-virt | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-devel | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-devel-matched | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-doc | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-headers | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-modules | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-modules-core | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-modules-extra | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-modules-extra-matched | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-rt | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-rt-64k | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
| AlmaLinux:10 | kernel-rt-64k-core | before 6.12.0-211.58.1.el10_2 | 6.12.0-211.58.1.el10_2 |
+96
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-68153Aug 10, 2026 · libceph: remove debugfs files before client teardown31Monitor
- ← EarlierCVE-2026-68154Aug 10, 2026 · libceph: reject zero bucket types in crush_decode39Monitor
- Later →CVE-2026-68156Aug 10, 2026 · libceph: refresh auth->authorizer_buf{,_len} after authorizer update39Monitor
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 | 0591a15815b498be628a937146e44487d599ba33 | Vendor (CNA) |
| Linux Linux | 3b249546f59c3d6d3592c10657f82bc3f1faa07c | Vendor (CNA) |
| Linux Linux | 40480eee361ed9676b3f844d532ac28b47251634 | Vendor (CNA) |
| Linux Linux | ba5f0015bfd376d764163045a61c17be75f44dae | Vendor (CNA) |
| Linux Linux | caf082ef8609a6ac26159ce115f55ab7d00231a3 | Vendor (CNA) |
| Linux Linux | cd0d41bc569632eaaeccde9d2a6bc919ec00c407 | Vendor (CNA) |
| Linux Linux | e3ccd4ecab09b22f507f49cb7ed9990c7158ceab | Vendor (CNA) |
| Linux Linux | e67e8b694872c9bc66996040f9de9242f6236ed9 | Vendor (CNA) |
| almalinux:kernel | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-core | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-debug | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-debug-core | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-debug-devel | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-debug-devel-matched | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-debug-modules | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-debug-modules-core | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-debug-modules-extra | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-devel | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:kernel-64k-devel-matched | 5.14.0-687.50.1.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| debian:linux | 6.1.187-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.101-1~deb12u1 · Debian:12 | Package registry (OSV) |
| red hat:kernel-64k-debug-debuginfo | 0:5.14.0-687.50.1.el9_8 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-64k-debug-devel | 0:5.14.0-687.50.1.el9_8 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-64k-debug-devel-matched | 0:5.14.0-687.50.1.el9_8 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-64k-debuginfo | 0:5.14.0-687.50.1.el9_8 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-64k-devel | 0:5.14.0-687.50.1.el9_8 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-64k-devel-matched | 0:5.14.0-687.50.1.el9_8 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debug-debuginfo | 0:5.14.0-687.50.1.el9_8 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debug-devel | 0:5.14.0-687.50.1.el9_8 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
+17
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.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-681540 days apartlibceph: reject zero bucket types in crush_decode39Monitor
- CVE-2026-684775 days apartipvs: fix more places with wrong ipv6 transport offsets39Monitor
- CVE-2026-720655 days apartnet: mana: Validate the packet length reported by the NIC39Monitor
- CVE-2026-9999966 days apartipv4: validate checksum_start before completing checksum37Monitor
- CVE-2026-681990 days apartwifi: ath6kl: fix OOB access from firmware ADDBA window size35Monitor
- CVE-2026-684543 days apartKVM: s390: pci: Fix handling of AIF enable without AISB35Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0800 · Aug 11, 2026(Linux Kernel Güvenlik Bildirimi)
Technical details
Attack conditions
- 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.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (7 more)Show less
- git.kernel.org/stable/c/3b249546f59c3d6d3592c10657f82bc3f1faa07c
- git.kernel.org/stable/c/40480eee361ed9676b3f844d532ac28b47251634
- git.kernel.org/stable/c/ba5f0015bfd376d764163045a61c17be75f44dae
- git.kernel.org/stable/c/caf082ef8609a6ac26159ce115f55ab7d00231a3
- git.kernel.org/stable/c/cd0d41bc569632eaaeccde9d2a6bc919ec00c407
- git.kernel.org/stable/c/e3ccd4ecab09b22f507f49cb7ed9990c7158ceab
- git.kernel.org/stable/c/e67e8b694872c9bc66996040f9de9242f6236ed9
Vendor advisories and official records. Exploit/PoC links are deliberately left out.