CVE-2026-87877
Description
A flaw was found in zstd-jni. An attacker could exploit a use-after-free vulnerability by calling specific methods on closed streams without proper validation. This could lead to memory corruption, potentially allowing the attacker to corrupt unrelated objects or cause the Java Virtual Machine (JVM) to crash, resulting in a denial of service.
Statement
Red Hat has determined that CVE-2026-87877 affects Red Hat products that include the zstd-jni library in a vulnerable version. The vulnerability can allow memory corruption or denial of service when specific stream methods are called after the stream has been closed.
Mitigation
No complete workaround is currently available. As a temporary measure, applications using zstd-jni should not call setDict(), setLongMax(), setLevel(), or setRefMultipleDDicts() on a stream after close(). Upgrade to a Red Hat product release containing zstd-jni 1.5.7-14 or later when available.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.7 | N/A | 7.7 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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