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NVD / CVE Program· CNA redhat

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

MediumCVSS 4.2 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 16/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.25% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. Special conditions such as timing or configuration are required.
  • Fixed version: libsoup (openSUSE:Leap 16.0) 3.6.6-160000.5.1; libsoup (openSUSE:Tumbleweed) 3.6.6-8.1; libsoup2 (openSUSE:Tumbleweed) 2.74.3-22.1.

Low priority for now. Upgrade to libsoup (openSUSE:Leap 16.0) 3.6.6-160000.5.1; libsoup (openSUSE:Tumbleweed) 3.6.6-8.1; libsoup2 (openSUSE:Tumbleweed) 2.74.3-22.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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
Nov 5, 2026
EPSS
0.2% · 17th percentile

Report tools

JSON

Action score

16

Monitor

Low priority for now.

CVSS
16 / 40 · 4.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · redhat
4.2
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-12548

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
gnomelibsoup
redhatenterprise linux

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • Red Hat Red Hat Enterprise Linux 10

    • all versionsaffected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • gnome libsoupall versions
  • redhat enterprise linux10.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12libsoup2.4from 0—
Debian:12libsoup3from 0—
openSUSE:Leap 16.0libsoupbefore 3.6.6-160000.5.13.6.6-160000.5.1
openSUSE:Tumbleweedlibsoupbefore 3.6.6-8.13.6.6-8.1
openSUSE:Tumbleweedlibsoup2before 2.74.3-22.12.74.3-22.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSlibsoupbefore 3.0.4-150400.3.55.13.0.4-150400.3.55.1
SUSE:Linux Enterprise Micro 5.3libsoup2before 2.74.3-150400.3.40.12.74.3-150400.3.40.1
SUSE:Linux Enterprise Micro 5.3libsoup2before 2.74.3-150400.3.43.12.74.3-150400.3.43.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7libsoupbefore 3.4.4-150600.3.59.13.4.4-150600.3.59.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7libsoupbefore 3.4.4-150600.3.50.13.4.4-150600.3.50.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7libsoup2before 2.74.3-150600.4.42.12.74.3-150600.4.42.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7libsoup2before 2.74.3-150600.4.39.12.74.3-150600.4.39.1
SUSE:Linux Enterprise Server 12 SP5-LTSSlibsoupbefore 2.62.2-5.49.12.62.2-5.49.1
SUSE:Linux Enterprise Server 16.0libsoupbefore 3.6.6-160000.5.13.6.6-160000.5.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5libsoupbefore 2.62.2-5.46.12.62.2-5.46.1
SUSE:Linux Micro 6.0libsoupbefore 3.4.2-159998.1.13.4.2-159998.1.1

Same product

gnome: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-2885An exploitable stack based buffer overflow vulnerability exists in the GNOME libsoup 2.58.
    46Plan
  • CVE-2019-17266libsoup from versions 2.65.1 until 2.68.1 have a heap-based buffer over-read because soup_ntlm_parse_challenge() in soup-auth-ntlm.c does…
    40Plan
  • CVE-2018-12910The get_cookies function in soup-cookie-jar.c in libsoup 2.63.2 allows attackers to have unspecified impact via an empty hostname.
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-5119Mar 30, 2026 · Libsoup: libsoup: information disclosure via cleartext transmission of cookies during https tunnel establishment
    32Monitor
  • ← EarlierCVE-2026-2708Apr 23, 2026 · Libsoup: libsoup: http request smuggling via duplicate content-length headers
    21Monitor
  • Later →CVE-2026-66337Jul 24, 2026 · Libsoup: libsoup: heap buffer over-read via integer underflow in soup_filter_input_stream_read_until()
    26Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:libsoup33.8.0-1 · Debian:14Package registry (OSV)
opensuse:libsoup3.6.6-8.1 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:libsoup22.74.3-22.1 · openSUSE:TumbleweedPackage registry (OSV)
suse:libsoup3.4.2-159998.1.1 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:libsoup3.4.4-150600.3.50.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:libsoup22.74.3-150400.3.40.1 · SUSE:Linux Enterprise Micro 5.3Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-10256070 days apartLibsoup: libsoup: heap buffer overflow during outgoing permessage-deflate buffer growth
    39Monitor
  • CVE-2026-10255770 days apartLibsoup: libsoup: heap buffer overflow during websocket message reassembly
    34Monitor
  • CVE-2026-10255870 days apartLibsoup: libsoup: heap buffer overflow during websocket receive-buffer growth
    34Monitor
  • CVE-2026-10255970 days apartLibsoup: libsoup: heap buffer overflow during websocket client-frame masking
    34Monitor
  • CVE-2026-10255570 days apartLibsoup: libsoup: heap buffer overflow via uninitialized length in data-uri base64 decoding
    32Monitor
  • CVE-2026-663373 days apartLibsoup: libsoup: heap buffer over-read via integer underflow in soup_filter_input_stream_read_until()
    26Monitor

Not on record for this CVE: patch commit or PR link · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
low · data can be read
Integrity
none
Availability
low · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
None
Availability impact
Low

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records