Medium Memory corruption exploit reference

CVE-2026-12548 — Libsoup: heap out-of-bounds read in libsoup due to integer truncation

A heap out-of-bounds read flaw was found in libsoup. When parsing multipart HTTP messages, an integer type mismatch between the caller and soup_headers_parse() can cause the length parameter to be incorrectly truncated, leading to a heap buffer over-read. A remote attacker could use this flaw to crash an application using libsoup or potentially disclose heap memory contents.

Published Jul 21, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: redhat

Low

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

Technical severity (medium)+3
CISA SSVC: exploitation "poc"+5

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

—

No EPSS score.

Affects

Gnome

Libsoup and 2 more

CVSS base

4.2

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Proof of concept

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

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

Documented mitigation — gitlab.gnome.org (NIST National Vulnerability Database)

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.

Identify exposed assets running the affected vendor/product/version combinations (Gnome Libsoup, Red Hat Enterprise Linux, Red Hat Red Hat Enterprise Linux 10).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the documented mitigations until a definitive fix is available.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Gnome	Libsoup	versions not specified by the source	Vulnerable	NIST National Vulnerability Database
Red Hat	Enterprise Linux	version 10.0	Vulnerable	NIST National Vulnerability Database
Red Hat	Red Hat Enterprise Linux 10	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

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

Attack vector

Network

Attack complexity

High

Privileges required

None

User interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

Low

Every base score collected

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

Score	Version	Severity	Expl.	Impact	Scored by
4.2	CVSS 3.1	Medium	1.6	2.5	secalert@redhat.com via NIST National Vulnerability Database
4.2	CVSS 3.1	Medium	—	—	redhat via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:L (score shown at the top: secalert@redhat.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-125 · Out-of-bounds Read

Other CVEs with this weakness →

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).
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · red hat/red hat enterprise linux 10
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
Fix documented
Oct 15, 2026 · NIST National Vulnerability Database
CVSS changed · 4.2
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Jul 21, 2026 · redhat

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

3 on the record

gitlab.gnome.org/GNOME/libsoup/-/work_items/512
Exploit, Mitigation, Vendor Advisory, NIST National Vulnerability Database
access.redhat.com/security/cve/CVE-2026-12548
Vendor Advisory, vdb-entry, x_refsource_REDHAT, NIST National Vulnerability Database
bugzilla.redhat.com/show_bug.cgi
Exploit, Issue Tracking, Vendor Advisory, issue-tracking, x_refsource_REDHAT, NIST National Vulnerability Database

Elsewhere on this site

Gnome
every CVE for this vendor

Memory corruption
same class

CWE-125
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-110924 Openssh: openssh: gssapi delegated credentials can be stored after a failed authentication 11h
Medium CVE-2026-110927 Openssh: openssh: a compressed payload can expand past the maximum packet size 11h
Medium CVE-2026-110926 Openssh: openssh: shared lz77 compression dictionary leaks plaintext across channels 19h
Medium CVE-2026-110923 Openssh: openssh: sftp can write outside the destination directory from a server-supplied path 19h
Medium CVE-2026-110925 Openssh: openssh: '$' and '\' in a command-line username expand through %u 19h
High CVE-2026-86848 Dpdk: dpdk: time-of-check/time-of-use vulnerability allowing guest-triggered out-of-bounds write in vhost-crypto 1d

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 FIRST EPSS score.
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-2026-12548 is "Libsoup: heap out-of-bounds read in libsoup due to integer truncation", rated Medium. It affects Libsoup (Gnome); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.2 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.