Avast antivirus heap buffer OOB read when scanning a malformed Mach-O file
Heap buffer out-of-bounds read vulnerability in Avast Antivirus when scanning a malformed Mach-O file may allow Local Execution of Code or Denial-of-Service of the antivirus process. This issue affects Avast Antivirus, AVG Antivirus, Norton Antivirus, Avast One, and Avast Business Antivirus on Windows, macOS, and Linux for virus definition builds before VPS 25090300. The affected scanning logic is delivered through a shared Gen Digital virus definition update stream. The same stream feeds the consumer antivirus products listed in this advisory and other Gen Digital products that embed the same engine. Mitigation flows through this update channel; installations at or above the listed build are not vulnerable regardless of which product consumes the stream.
- Published
- Dec 1, 2025
- Updated
- Sep 25, 2026
- EPSS
- 0.2% · 7th percentile
- CWE
- CWE-125
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · NLOK
- 7.8
- 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.
Affected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (NLOK). Independent of NVD's CPE analysis and usually ahead of it.
Gen Digital Avast Antivirus
- before 25090300affected
Gen Digital Avast Business Antivirus
- before 25090300affected
Gen Digital Avast One
- before 25090300affected
Gen Digital AVG Antivirus
- before 25090300affected
Gen Digital Norton Antivirus
- before 25090300affected
Same product
gen digital: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-7011Avast antivirus heap OOB when scanning a malformed zip file31Monitor
- CVE-2025-7009Avast antivirus heap buffer OOB read when scanning a malformed PE file31Monitor
- CVE-2025-7008Avast antivirus heap buffer OOB read when scanning a malformed PE file31Monitor
- CVE-2025-7004Avast antivirus heap buffer OOB write when scanning a malformed PE file31Monitor
- CVE-2025-7019Avast antivirus stack overflow when scanning a malformed Office Open XML file22Monitor
- CVE-2025-7010Avast antivirus stack overflow when scanning a malformed PDF file22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
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.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2025-7008193 days apartAvast antivirus heap buffer OOB read when scanning a malformed PE file31Monitor
- CVE-2025-7009193 days apartAvast antivirus heap buffer OOB read when scanning a malformed PE file31Monitor
- CVE-2025-7011193 days apartAvast antivirus heap OOB when scanning a malformed zip file31Monitor
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
- Someone with local access to the system 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
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-125 · Out-of-bounds ReadCVSS vector
CVSS:3.1/AV:L/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
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.