CVE-2019-18885: fs/btrfs/volumes.c in the Linux kernel before 5.1 allows a btrfs_verify_dev_extents NULL pointer dereference via a crafted btrfs image becau
Noroxi assessment
Priority: Monitor (action score 22/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 1.2% (FIRST EPSS); higher than 68.5% of all records.
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: linux (Debian:12) 5.2.6-1; linux-4.19 (Debian:9) 4.19.132-1~deb9u2.
- Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to linux (Debian:12) 5.2.6-1; linux-4.19 (Debian:9) 4.19.132-1~deb9u2 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
fs/btrfs/volumes.c in the Linux kernel before 5.1 allows a btrfs_verify_dev_extents NULL pointer dereference via a crafted btrfs image because fs_devices->devices is mishandled within find_device, aka CID-09ba3bc9dd15.
- Published
- Nov 14, 2019
- Updated
- Jun 16, 2026
- EPSS
- 1.2% · 68th percentile
- CWE
- CWE-476
Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.2%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- 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.
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernelbefore 5.1
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 5.2.6-1 | 5.2.6-1 |
| Debian:9 | linux-4.19 | before 4.19.132-1~deb9u2 | 4.19.132-1~deb9u2 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- 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 KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2019-18806Nov 7, 2019 · A memory leak in the ql_alloc_large_buffers() function in drivers/net/ethernet/qlogic/qla3xxx.c in the Linux kernel before 5.3.5 allows loca22Monitor
- ← EarlierCVE-2007-3732Nov 7, 2019 · In Linux 2.6 before 2.6.23, the TRACE_IRQS_ON function in iret_exc calls a C function without ensuring that the segments are set properly.22Monitor
- Later →CVE-2019-19043Nov 18, 2019 · A memory leak in the i40e_setup_macvlans() function in drivers/net/ethernet/intel/i40e/i40e_main.c in the Linux kernel through 5.3.11 allows22Monitor
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 |
|---|---|---|
| debian:linux | 5.2.6-1 · Debian:12 | Package registry (OSV) |
| debian:linux-4.19 | 4.19.132-1~deb9u2 · Debian:9 | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:2 | 2019-11-12 |
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.
- First PoC-2 d
- Published
- TodayOct 30, 2026+2542 d
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
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.
No nightly-computed relations.
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-21-0331 · Apr 21, 2021(Oracle Güvenlik Uyarısı Yayınladı)
- TR-20-057 · Jan 27, 2020(Linux Kernel Güvenlik Güncellemesi)
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- 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
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-476 · NULL Pointer DereferenceCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (10 more)Show less
- git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=09ba3bc9dd150457c506e4661380a6183af651c1
- github.com/torvalds/linux/commit/09ba3bc9dd150457c506e4661380a6183af651c1
- lists.debian.org/debian-lts-announce/2020/08/msg00019.html
- security.netapp.com/advisory/ntap-20191205-0001/
- usn.ubuntu.com/4254-1/
- usn.ubuntu.com/4254-2/
- usn.ubuntu.com/4258-1/
- usn.ubuntu.com/4287-1/
- usn.ubuntu.com/4287-2/
- www.oracle.com/security-alerts/cpuApr2021.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.