CVE-2026-58012

Description

A flaw was found in GLib. A buffer over-read can occur in the g_regex_replace function when used with the `G_REGEX_RAW` compile flag and case-change replacement escapes because the string_append function processes matched substrings using UTF-8 functions that assume valid UTF-8 input, even when the string is treated as raw bytes. This vulnerability can cause a minor information disclosure of 1-5 bytes and a denial of service when the buffer over-read crosses a page boundary.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

EPSS — Exploit Prediction

0.0032

Probability of exploitation

0.24%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-126 CWE-126

Affected Products

Vendor	Product	Versions
gnome	glib	< 2.86.5
gnome	glib	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All

References

Advisories & Patches

https://gitlab.gnome.org/GNOME/glib/-/issues/3918

Exploits

https://gitlab.gnome.org/GNOME/glib/-/issues/3918

Other References

https://access.redhat.com/security/cve/CVE-2026-58012 https://bugzilla.redhat.com/show_bug.cgi?id=2492247

Frequently Asked Questions

What is CVE-2026-58012? +

A flaw was found in GLib. A buffer over-read can occur in the g_regex_replace function when used with the `G_REGEX_RAW` compile flag and case-change replacement escapes because the string_append function processes matched substrings using UTF-8 functions that assume valid UTF-8 input, even when the string is treated as raw bytes. This vulnerability can cause a minor information disclosure of 1-5 bytes and a denial of service when the buffer over-read crosses a page boundary. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-58012? +

CVE-2026-58012 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0032, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-58012? +

CVE-2026-58012 affects products from gnome, redhat, specifically: enterprise_linux, glib. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-58012? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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