// For flags

CVE-2025-31115

XZ has a heap-use-after-free bug in threaded .xz decoder

Severity Score

8.7
*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

XZ Utils provide a general-purpose data-compression library plus command-line tools. In XZ Utils 5.3.3alpha to 5.8.0, the multithreaded .xz decoder in liblzma has a bug where invalid input can at least result in a crash. The effects include heap use after free and writing to an address based on the null pointer plus an offset. Applications and libraries that use the lzma_stream_decoder_mt function are affected. The bug has been fixed in XZ Utils 5.8.1, and the fix has been committed to the v5.4, v5.6, v5.8, and master branches in the xz Git repository. No new release packages will be made from the old stable branches, but a standalone patch is available that applies to all affected releases.

XZ Utils proporciona una librería de compresión de datos de propósito general, además de herramientas de línea de comandos. En XZ Utils 5.3.3alpha a 5.8.0, el decodificador .xz multiproceso de liblzma presenta un error que provoca un fallo en la ejecución de una entrada no válida. Esto afecta a use after free y a la escritura en una dirección basada en el puntero nulo y un desplazamiento. Las aplicaciones y librerías que utilizan la función lzma_stream_decoder_mt se ven afectadas. El error se ha corregido en XZ Utils 5.8.1 y la corrección se ha implementado en las ramas v5.4, v5.6, v5.8 y master del repositorio Git de xz. No se crearán nuevos paquetes de versiones a partir de las ramas estables antiguas, pero existe un parche independiente disponible para todas las versiones afectadas.

Harri K. Koskinen discovered that XZ Utils incorrectly handled the threaded xz decoder. If a user or automated system were tricked into processing an xz file, a remote attacker could use this issue to cause XZ Utils to crash, resulting in a denial of service, or possibly execute arbitrary code.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
System
Vulnerable | Subsequent
Confidentiality
None
None
Integrity
None
None
Availability
High
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-03-26 CVE Reserved
  • 2025-04-03 CVE Published
  • 2025-04-03 CVE Updated
  • 2025-04-04 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-366: Race Condition within a Thread
  • CWE-416: Use After Free
  • CWE-476: NULL Pointer Dereference
  • CWE-826: Premature Release of Resource During Expected Lifetime
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Tukaani-project
Search vendor "Tukaani-project"
 XZ
Search vendor "Tukaani-project" for product "XZ"
 >= 5.3.3 < 5.8.1
Search vendor "Tukaani-project" for product "XZ" and version " >= 5.3.3 < 5.8.1"
en
Affected