CVE-2026-31580 — bcache: fix cached_dev.sb_bio use-after-free and crash
In the Linux kernel, the following vulnerability has been resolved: bcache: fix cached_dev.sb_bio use-after-free and crash In our production environment, we have received multiple crash reports regarding libceph, which have caught our attention: ``` [6888366.280350] Call Trace: [6888366.280452] blk_update_request+0x14e/0x370 [6888366.280561] blk_mq_end_request+0x1a/0x130 [6888366.280671] rbd_img_handle_request+0x1a0/0x1b0 [rbd] [6888366.280792] rbd_obj_handle_request+0x32/0x40 [rbd] [6888366.280903] __complete_request+0x22/0x70 [libceph] [6888366.281032] osd_dispatch+0x15e/0xb40 [libceph] [6888366.281164] ? inet_recvmsg+0x5b/0xd0 [6888366.281272] ? ceph_tcp_recvmsg+0x6f/0xa0 [libceph] [6888366.281405] ceph_con_process_message+0x79/0x140 [libceph] [6888366.281534] ceph_con_v1_try_read+0x5d7/0xf30 [libceph] [6888366.281661] ceph_con_workfn+0x329/0x680 [libceph] ``` After analyzing the coredump file, we found that the address of dc->sb_bio has been freed. We know that cached_dev is only freed when it is stopped. Since sb_bio is a part of struct cached_dev, rather than an alloc every time. If the device is stopped while writing to the superblock, the released address will be accessed at endio. This patch hopes to wait for sb_write to complete in cached_dev_free. It should be noted that we analyzed the cause of the problem, then tell all details to the QWEN and adopted the modifications it made.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060 and < 81f44ed8c3f54abb7561ece774ea4cca5070b2f2≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060 and < f50e7c325ab1207fe941555bcff659f6d7050572≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060 and < 9467d360be70e6ee55b0c1cd2a1f1424f57b5b85≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060 and < 47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060 and < add4982510f3b7c318a2dd7438bdc9c63171e753≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060 and < 2d6965581e164fa2ba3f7652ddae5535f6336576≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060 and < 4f71c8ba2dc009042493021d94a9718fbe2ebf27≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060 and < 383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9 and 2 more≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060 and < fec114a98b8735ee89c75216c45a78e28be0f128version 3.10 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | < 6.6.136≥ 6.12 and < 6.12.83≥ 6.13 and < 6.18.24≥ 6.19 and < 6.19.14≥ 7.0 and < 7.0.1 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.17%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 7.8
- Source status changed · → Modified
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 15, 2026 – Oct 15, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
10 on the record
- git.kernel.org/stable/c/47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1
- git.kernel.org/stable/c/fec114a98b8735ee89c75216c45a78e28be0f128
- git.kernel.org/stable/c/add4982510f3b7c318a2dd7438bdc9c63171e753
- git.kernel.org/stable/c/2d6965581e164fa2ba3f7652ddae5535f6336576
- git.kernel.org/stable/c/383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9
- git.kernel.org/stable/c/4f71c8ba2dc009042493021d94a9718fbe2ebf27
- git.kernel.org/stable/c/9467d360be70e6ee55b0c1cd2a1f1424f57b5b85
- cert-portal.siemens.com/productcert/html/ssa-784472.html
- git.kernel.org/stable/c/f50e7c325ab1207fe941555bcff659f6d7050572
- git.kernel.org/stable/c/81f44ed8c3f54abb7561ece774ea4cca5070b2f2
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 13h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 13h
- Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
- Unknown CVE-2026-98428 ALSA: usb: 6fire: Avoid embedded URBs 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-31580 is "bcache: fix cached_dev.sb_bio use-after-free and crash", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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