Xen libfsimage Rock Ridge extension integer overflow

Summaryinfo

A vulnerability has been found in Xen libfsimage and classified as very critical. This affects an unknown part of the component Rock Ridge extension. This manipulation causes integer overflow. The identification of this vulnerability is CVE-2026-62425. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as very critical was found in Xen libfsimage (the affected version unknown). Affected by this vulnerability is an unknown part of the component Rock Ridge extension. The manipulation with an unknown input leads to a integer overflow vulnerability. The CWE definition for the vulnerability is CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] The directory and Rock Ridge / SUSP walk in libfsimage's iso9660 driver derives several lengths directly from attacker-controlled on-disk fields without validating them: * The directory loop itself assumes a good record length. This is CVE-2026-42494. * The calculation of the System Use area may underflow. This is CVE-2026-42495. * The Rock Ridge extension loop assumes a good (inner) record length. This is CVE-2026-62423. * The Rock Ridge NM record processing assumes a good entry length. This is CVE-2026-62424. * The Rock Ridge CE record processing assumes a good size and offset. This is CVE-2026-62425.

The advisory is shared at xenbits.xenproject.org. This vulnerability is known as CVE-2026-62425 since 07/14/2026. The exploitation appears to be easy. The attack can be launched remotely. Additional levels of successful authentication are needed for exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/02/2026).

The vulnerability scanner Nessus provides a plugin with the ID 331597 (Fedora 44 : xen (2026-bf1da84dfc)), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at CNNVD (CNNVD-2026-91688833), Tenable (331597) and CERT Bund (WID-SEC-2026-2568). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Open Source Xen

Productinfo

Type

• Virtualization Software

Vendor

• Xen

Name

• libfsimage

License

• open-source

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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Exploitinginfo

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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