CVE-2026-58010
Description
A flaw was found in GLib. An off-by-one error can occur in the gvs_tuple_is_normal function in the glib/gvariant-serialiser.c file when doing an alignment padding check because the bounds check uses > instead of >=, causing an out-of-bounds read of only 1 byte. This issue can cause a minor information disclosure of 1 byte and a denial of service when the out-of-bounds read crosses a page boundary.
Statement
Any applications calling the g_variant_is_normal_form(), g_variant_get_normal_form() or g_variant_byteswap() functions that process untrusted GVariant data received from D-Bus, network or file are vulnerable to this issue. This flaw can cause an out-of-bounds read of only 1 byte, leading to an information disclosure of only 1 byte and a denial of service when the out-of-bounds read crosses a page boundary. Due to these reasons, this vulnerability has been rated with a moderate severity.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | 8.2 | 6.5 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | Low | Low |
| Integrity Impact | None | None | None |
| Availability Impact | Low | High | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
Red Hat CVSS v3 Score Explanation
A denial of service can occur due to an application crash when the out-of-bounds read crosses a page boundary, which is very unlikely in heap allocations. The crash can be reliably reproduced in ASan builds, but not in production environments. To reflect this condition, the availability metric is set to low.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
Confidentiality
Technical Impact: Bypass Protection Mechanism
By reading out-of-bounds memory, an attacker might be able to get secret values, such as memory addresses, which can bypass protection mechanisms such as ASLR in order to improve the reliability and likelihood of exploiting a separate weakness to achieve code execution instead of just denial of service.
Availability,Integrity
Technical Impact: DoS: Crash, Exit, or Restart
An attacker might be able to cause a crash or other denial of service by causing the product to read a memory location that is not allowed (such as a segmentation fault), or to cause other conditions in which the read operation returns more data than is expected.
Acknowledgements
Red Hat would like to thank linhlhq for reporting this issue.
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