CVE-2026-102555

Libsoup: libsoup: heap buffer overflow via uninitialized length in data-uri base64 decoding

HIGH
8.2
CVSS Score
Published: September 29, 2026 at 05:15 PM UTC
Updated: October 15, 2026 at 05:17 PM UTC
2 products affected across 2 vendorsEnterprise LinuxLibsoup

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Severity
HIGH8.2
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

A flaw was found in libsoup. The soup_uri_decode_data_uri() function incorrectly treated base64 data-URI payloads as NUL-terminated strings when calling g_base64_decode_inplace(). If the percent-decoded payload contained embedded NUL bytes, the decoded length could remain uninitialized and be used as the size of the returned GBytes. This can lead to an out-of-bounds read or application crash when processing a crafted data URI.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.7.3
Vendor states this is fixed in 0:3.6.5-3.el10_2.20 (unaffected)
Vendor states this is fixed in 7 (unaffected)
Vendor states this is fixed in 8 (unaffected)
Vendor states this is fixed in 6 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

VDB Entryx_refsource_REDHATMitigationVendor Advisory
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-102555
Issue Trackingx_refsource_REDHATVendor Advisory
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2543224
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:83618

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.2HIGHredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

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