CVE-2026-48095: GHSL-2026-140_7-Zip: 7-Zip has a heap buffer overflow via NTFS compressed stream buffer under-allocation
Noroxi assessment
Priority: Monitor (action score 35/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 1.1% (FIRST EPSS); higher than 66% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
- Fixed version: 7zip (Alpine:v3.24) 26.01-r0; 7zip (Debian:12) 22.01+really26.01+dfsg-0+deb12u1; p7zip (Debian:12) 16.02+really26.01+dfsg-0+deb12u1.
Low priority for now. Upgrade to 7zip (Alpine:v3.24) 26.01-r0; 7zip (Debian:12) 22.01+really26.01+dfsg-0+deb12u1; p7zip (Debian:12) 16.02+really26.01+dfsg-0+deb12u1 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
7-Zip is a file archiver with a high compression ratio. Versions 26.00 and prior contain a heap buffer overflow vulnerability caused by an under-allocation in the NTFS compressed stream buffer (GetCuSize shift UB), potentially allowing attackers to cause arbitrary code execution or application crashes. CInStream::GetCuSize() in the NTFS handler computes the compression-unit buffer size as (UInt32)1 << (BlockSizeLog + CompressionUnit), and a crafted image with ClusterSizeLog >= 28 and CompressionUnit == 4 drives the exponent to 32, which is undefined behavior and collapses on x86/x64 so _inBuf is allocated as 1 byte. ReadStream_FALSE then writes up to 256 MB of attacker-controlled data into that 1-byte buffer in 64 KB iterations, and because the CInStream object sits only 304 bytes after _inBuf, its vtable pointer is overwritten and the next dispatched call achieves a vtable hijack. On 32-bit builds the overflow is unconditionally reached; on 64-bit it requires the parallel 8 GB _outBuf allocation to succeed, otherwise failing closed to denial of service. The NTFS handler is enabled by default in stock 7z.dll and, via signature-based fallback matching "NTFS " at offset 3, will open a crafted image regardless of file extension during extraction or testing. Version 26.01 fixes the issue.
- Published
- Jun 5, 2026
- Updated
- Jun 17, 2026
- EPSS
- 1.1% · 66th percentile
- CWE
- CWE-190
Report tools
Action score
35
Monitor
Low priority for now.
- CVSS
- 35 / 40 · 8.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.1%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 8.8
- 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
- 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 |
|---|---|---|
| 7-zip | 7-zip | cpe:2.3:a:7-zip:7-zip |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- 7-zip 7-zipbefore 26.01
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
mcmilk 7-Zip
- <= 26.00affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.24 | 7zip | before 26.01-r0 | 26.01-r0 |
| Debian:12 | 7zip | before 22.01+really26.01+dfsg-0+deb12u1 | 22.01+really26.01+dfsg-0+deb12u1 |
| Debian:12 | p7zip | before 16.02+really26.01+dfsg-0+deb12u1 | 16.02+really26.01+dfsg-0+deb12u1 |
| Debian:13 | 7zip | from 0 | — |
| Debian:13 | p7zip | before 16.02+transitional.1 | 16.02+transitional.1 |
| Debian:14 | 7zip | before 26.01+dfsg-1 | 26.01+dfsg-1 |
| openSUSE:Leap 16.0 | 7zip | before 26.01-160000.1.1 | 26.01-160000.1.1 |
| openSUSE:Tumbleweed | 7zip | before 26.01-1.1 | 26.01-1.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | 7zip | before 26.01-150400.9.6.1 | 26.01-150400.9.6.1 |
| SUSE:Linux Enterprise Server 16.0 | 7zip | before 26.01-160000.1.1 | 26.01-160000.1.1 |
Same product
7-zip: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-04117-Zip Mark-of-the-Web Bypass VulnerabilityKEV78This week
- CVE-2023-31102Ppmd7.c in 7-Zip before 23.00 allows an integer underflow and invalid read operation via a crafted 7Z archive.47Plan
- CVE-2008-6536Unspecified vulnerability in 7-zip before 4.5.7 has unknown impact and remote attack vectors, as demonstrated by the PROTOS GENOME test suit41Plan
Published before and after this one in the same product
- ← EarlierCVE-2025-11002Jan 23, 2026 · 7-Zip ZIP File Parsing Directory Traversal Remote Code Execution Vulnerability31Monitor
- ← EarlierCVE-2026-48092Jun 5, 2026 · 7-Zip SquashFS Fragment Offset Overflow (GHSL-2026-116)33Monitor
- Later →CVE-2026-48101Jun 5, 2026 · GHSL-2026-117: 7-Zip UEFI Capsule uninitialized heap memory disclosure26Monitor
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 |
|---|---|---|
| alpine:7zip | 26.01-r0 · Alpine:v3.24 | Package registry (OSV) |
| debian:7zip | 22.01+really26.01+dfsg-0+deb12u1 · Debian:12 | Package registry (OSV) |
| debian:p7zip | 16.02+really26.01+dfsg-0+deb12u1 · Debian:12 | Package registry (OSV) |
| opensuse:7zip | 26.01-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| suse:7zip | 26.01-160000.1.1 · SUSE:Linux Enterprise Server 16.0 | 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:3 | 2026-05-26 |
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-10 d
- Published
- TodayNov 1, 2026+149 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.
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.
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).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-190 · Integer Overflow or WraparoundCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.