CVE-2026-102703: arbitrary read/write via grant copy
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-04 15:41 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] A common access pattern is a batch of Grant Copy operations acting on adjacent address ranges in the same source or destination page. For performance reasons, Xen caches details internally to reuse already validated data. The conditions on when to re-validate the internal data were not correct in some cases: - Frame numbers and grant references could wrongly be mixed up. This is CVE-2026-102703. - Copying by frame number (rather than grant reference) is permitted only when operating on the caller’s own memory. The check to enforce this restriction was misplaced. This is CVE-2026-102704.
Description quoted from the CVE record (assigned by XEN, published 2026-11-04).
Weakness: CWE-704 Incorrect Type Conversion or Cast
How it can be exploited
Exploitable with local access with low attack complexity needing low privileges and no user interaction. Impact: confidentiality low, integrity low, availability none. CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: partial.
Public exploit evidence (Exploit Observer)
Exploit Observer has no public exploit code naming this CVE. Check Exploit Observer for anything new.
Live scores
- EPSS
- 0.000
low predicted chance of attack - VEDAS
- 0.040
little exploit evidence - On CISA KEV
- Not listed
- Detection rule
- No public rule yet
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Xen | Not stated | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
Advisories on this CVE
References
Other references
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.
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