CVE-2026-80558: Linux kernel · libceph: Avoid using invalid osd indices from primary_temp
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 26 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix for this vulnerability has been implemented in the Linux kernel by adding validation checks for osd indices from primary_temp in libceph. Users should apply the official kernel updates that include this patch to remediate the issue. Since this is a kernel vulnerability, updating to a patched kernel version is the recommended mitigation. Patch status is not explicitly stated in the provided data; users should consult their Linux distribution or vendor advisories for the specific fixed kernel versions.
Description
In the Linux kernel, the following vulnerability has been resolved: libceph: Avoid using invalid osd indices from primary_temp A corrupted osdmap received from a Ceph monitor or OSD may contain osd indices in its pg_temp, primary_temp, pg_upmap, and pg_upmap_items parts that don't exist, i.e., that are greater than max_osd or smaller than CEPH_HOMELESS_OSD (-1). These indices are used to create the up and acting set in ceph_pg_to_up_acting_osds(), called from calc_target(). While most of these osd indices are checked, the one from primary_temp is not. Subsequently, this may lead to calc_target() returning this (potentially invalid) index as target osd for a (linger) request. Because the osd_state, osd_weight, and osd_addr arrays only contain max_osd entries (with indices 0 to max_osd -1), this leads to out-of-bounds accesses when trying to read values from these arrays. This patch fixes the issue by adding a check to get_temp_osds(), so that only valid osd indices from primary_temp are used, and it falls back to using the primary from pg_temp or the up set if it is invalid. [ idryomov: changelog ]
References
- nvd.nist.gov/vuln/detail/CVE-2026-80558 (opens in a new tab)
- git.kernel.org/stable/c/1c705fe8e59c6b16f48964973fb23c8ec4735b73 (opens in a new tab)
- git.kernel.org/stable/c/3660b98d1204b419f6a77e9a295f148dcf38d042 (opens in a new tab)
- git.kernel.org/stable/c/4f392fec075562dc93bb0c69f37423ca2af9b48f (opens in a new tab)
- git.kernel.org/stable/c/505fc50b8ff8e687b7e3ef6866269dea27366224 (opens in a new tab)
- git.kernel.org/stable/c/6799d4a916ffcb3d450d8440f9fe0f0862f768d6 (opens in a new tab)
- git.kernel.org/stable/c/dfe1877d351b99eb1b1a62a3fc2d174220e88e20 (opens in a new tab)
- git.kernel.org/stable/c/e009c5f0ad634c62f5c48a41f1f3c019ecf52555 (opens in a new tab)
- git.kernel.org/stable/c/e2ffeec85201b2bb748e99e12539ee1b92f62796 (opens in a new tab)
- ubuntu.com/security/CVE-2026-80558 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80558 (opens in a new tab)