CVE Intelligence
Medium File handling exploit reference

CVE-2021-28153 — An issue was discovered in GNOME GLib before 2.66.8. When g_file_replace() is used with...

An issue was discovered in GNOME GLib before 2.66.8. When g_file_replace() is used with G_FILE_CREATE_REPLACE_DESTINATION to replace a path that is a dangling symlink, it incorrectly also creates the target of the symlink as an empty file, which could conceivably have security relevance if the symlink is attacker-controlled. (If the path is a symlink to a file that already exists, then the contents of that file correctly remain unchanged.)

Published Mar 11, 2021 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: mitre

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 2.6% (30-day exploitation probability)+13
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
2.62%
ahead of 85% of scored CVEs · Oct 14, 2026
Affects
Broadcom
Brocade Fabric Operating System Firmware and 3 more
CVSS base
5.3
Medium · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Broadcom Brocade Fabric Operating System Firmware, Debian Debian Linux, Fedoraproject Fedora…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Broadcom Brocade Fabric Operating System Firmware versions not specified by the source Vulnerable NIST National Vulnerability Database
Debian Debian Linux version 9.0 Vulnerable NIST National Vulnerability Database
Fedoraproject Fedora version 33 Vulnerable NIST National Vulnerability Database
Gnome Glib < 2.66.8 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
5.3 CVSS 3.1 Medium 3.9 1.4 nvd@nist.gov via NIST National Vulnerability Database
5.3 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
5.0 CVSS 2.0 Medium 10.0 2.9 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-59 · Link Following

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 2.62%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Monitor file creation in web directories and paths with traversal sequences (../).
web/proxy/WAF logsnetwork IDS/IPSfile integrity (FIM)endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Record published
    Oct 14, 2026
  • Fix documented
    Oct 14, 2026 · NIST National Vulnerability Database
  • Affected products added · gnome/glib, broadcom/brocade fabric operating system firmware, debian/debian linux, fedoraproject/fedora
    Oct 14, 2026 · NIST National Vulnerability Database
  • CVSS changed · 5.3
    Oct 14, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 14, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 14, 2026 · Alertas do Telegram
  • 2021
  • CVE published
    Mar 11, 2021 · mitre

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 14, 2026 – Oct 14, 2026
  • 1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

11 on the record

Elsewhere on this site

Broadcom
every CVE for this vendor
File handling
same class
CWE-59
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-12996 A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote... Jul 30, 2026
  • CVE-2026-14355 ext/openssl: Memory corruption in openssl_encrypt with AES-WRAP-PAD Jul 3, 2026
  • CVE-2026-58013 Glib: buffer over-read in glib/giochannel.c via "g_io_channel_read_line_backend" Jun 30, 2026
  • CVE-2026-58010 Glib: buffer over-read in glib/gvariant-serialiser.c via gvs_tuple_is_normal() Jun 30, 2026
  • CVE-2026-58011 Glib: out-of-bounds read in glib/gdatetime.c:g_date_time_get_ymd via invalid gdatetime Jun 30, 2026
  • CVE-2026-58012 Glib: buffer over-read in g_regex_replace() via glib/gregex.c:string_append() and g_utf8_next_char() Jun 30, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No CISA SSVC assessment.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2021-28153 is "An issue was discovered in GNOME GLib before 2.66.8. When g_file_replace() is used with...", rated Medium. It affects Brocade Fabric Operating System Firmware (Broadcom); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 2.62% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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