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

mediumCVSS 6.5CVE-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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: medium — CVSS 6.5
Published: 2026-06-30
Last updated: 2026-07-02
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-58012

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-580120.32% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 24% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-58012	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

mediumCVE-2026-58012: Glib: buffer over-read in g_regex_replace() via glib/gregex.c:string_append() and g_utf8_next_…msrc

Recent advisories for GLib. A buffer

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

mediumCVE-2026-58013: A flaw was found in GLib. A buffer over-read can occur in g_io_channel_read_line_backend() in …nvd · 2026-06-30
mediumCVE-2026-58010: Glib: buffer over-read in glib/gvariant-serialiser.c via gvs_tuple_is_normal()msrc · 2026-06-09
mediumCVE-2026-58012: Glib: buffer over-read in g_regex_replace() via glib/gregex.c:string_append() and g_utf8_next_…msrc · 2026-06-09
mediumCVE-2026-58013: Glib: buffer over-read in glib/giochannel.c via "g_io_channel_read_line_backend"msrc · 2026-06-09