Unknown

CVE-2026-80807 — nilfs2: reject invalid block index in GC ioctl

In the Linux kernel, the following vulnerability has been resolved: nilfs2: reject invalid block index in GC ioctl Syzbot reported list corruption caused by a double list_add_tail() call on bh->b_assoc_buffers within nilfs_lookup_dirty_data_buffers(). Analysis revealed that the root cause was the insertion of a page/folio with a page index of ULONG_MAX into the page cache via the GC ioctl. filemap_get_folios_tag(), called by nilfs_lookup_dirty_data_buffers(), repeatedly detects a dirty folio with a page index of ULONG_MAX due to index wrap-around, leading to duplicate processing of dirty buffers. As a preparatory step, the GC ioctl loads the page/folio of the block to be moved during GC and inserts it into the page cache based on information in the nilfs_vdesc structure passed as an argument. Normally, this does not cause issues because the user-space GC library configures the nilfs_vdesc structure properly. However, since there is no range check on the parameters determining the page index, a request with artificially crafted parameters -- such as those generated by Syzbot -- can result in a page/folio being inserted with a page index of ULONG_MAX, triggering the above problem. This resolves the issue by checking the ranges of 'vd_offset' and 'vd_vblocknr' in the nilfs_vdesc structure that determine the page index, thereby preventing the invalid page/folio insertions.

Published Sep 4, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1

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.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.2%

ahead of 10% of scored CVEs · Oct 26, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

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).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 7942b919f7321f95a777d396ff7894a7a83dc9b0 and < 898404cdf882d7b54f1132f75570984ca3214796≥ 7942b919f7321f95a777d396ff7894a7a83dc9b0 and < ba8a8b563a28d358c45c62a306d421434a058648≥ 7942b919f7321f95a777d396ff7894a7a83dc9b0 and < 3bd064ccc70b85f9a3d53aece29dc8473be5a226≥ 7942b919f7321f95a777d396ff7894a7a83dc9b0 and < a5e776e2937581d67ec5b9b4d27b0f70d7baa6b1≥ 7942b919f7321f95a777d396ff7894a7a83dc9b0 and < 68aa9ab6f8f2895713aa6ddf781463ed8ea5ba44≥ 7942b919f7321f95a777d396ff7894a7a83dc9b0 and < e447f7edb99bd00cec63d6f3049e2e5074946f71≥ 7942b919f7321f95a777d396ff7894a7a83dc9b0 and < ec6ddf271dfa4c7e3147bc2c8b2bad4315f316a1≥ 7942b919f7321f95a777d396ff7894a7a83dc9b0 and < fbcfb75c20d71a5b542ad4ac3b79d10b997c8152 and 2 more ≥ 7942b919f7321f95a777d396ff7894a7a83dc9b0 and < a1735eae55448bc79c2da6593455791e886f6ed8version 2.6.30	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 26, 2026 · 11 reading(s) · max 0.20%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 4, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 19, 2026 – Oct 19, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

11 on the record

git.kernel.org/stable/c/ba8a8b563a28d358c45c62a306d421434a058648
NIST National Vulnerability Database
git.kernel.org/stable/c/3bd064ccc70b85f9a3d53aece29dc8473be5a226
NIST National Vulnerability Database
github.com/advisories/GHSA-h6ww-mgj9-p3pf
GitHub Security Advisories
git.kernel.org/stable/c/a1735eae55448bc79c2da6593455791e886f6ed8
NIST National Vulnerability Database
git.kernel.org/stable/c/ec6ddf271dfa4c7e3147bc2c8b2bad4315f316a1
NIST National Vulnerability Database
git.kernel.org/stable/c/898404cdf882d7b54f1132f75570984ca3214796
NIST National Vulnerability Database
git.kernel.org/stable/c/fbcfb75c20d71a5b542ad4ac3b79d10b997c8152
NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-80807
GitHub Security Advisories
git.kernel.org/stable/c/68aa9ab6f8f2895713aa6ddf781463ed8ea5ba44
NIST National Vulnerability Database
git.kernel.org/stable/c/a5e776e2937581d67ec5b9b4d27b0f70d7baa6b1
NIST National Vulnerability Database
git.kernel.org/stable/c/e447f7edb99bd00cec63d6f3049e2e5074946f71
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-99092 riscv: patch: fix handling of bpf-jit execmem addresses 23h
Unknown CVE-2026-99093 mm: don't schedule deferred kernel page table freeing while booting 23h
Unknown CVE-2026-99095 drm/vc4: drain the hangcheck timer and works on V3D unbind 23h
Unknown CVE-2026-99096 io_uring/register: don't exempt disabled rings from task restrictions 23h
Unknown CVE-2026-99097 tee: shm: reject zero-sized allocations in tee_dyn_shm_alloc_helper() 23h
Unknown CVE-2026-99098 dm-integrity: fix buffer overflow in inline mode with large tag size 23h

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 CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
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-2026-80807 is "nilfs2: reject invalid block index in GC ioctl", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.20% 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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