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TI-2026-65420 Aliases CVE-2026-102555GHSA-vfxx-hcqj-vrh4

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

Priority MEDIUM 42CWE-125Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · None · High
Fix status
Partial Red Hat: 4 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00479 41st percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 4 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Red HatRed Hat Enterprise Linux 10—3.6.5-3.el10_2.20Patch availableCNA
Red HatRed Hat Enterprise Linux 10.0 Extended Update Support—3.6.5-3.el10_0.19Patch availableCNA
Red HatRed Hat Enterprise Linux 6——No fix listedCNA
Red HatRed Hat Enterprise Linux 7——Not affectedCNA
Red HatRed Hat Enterprise Linux 8——Not affectedCNA
Red HatRed Hat Enterprise Linux 9——No fix listedCNA
  • Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in 3.6.5-3.el10_2.20 Patch available CNA
  • Red Hat Enterprise Linux 10.0 Extended Update Support VendorRed Hat Affected — Fixed in 3.6.5-3.el10_0.19 Patch available CNA
  • Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — No fix listed CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:gnome:libsoup:*:*:*:*:*:*:*:*before 3.7.3VulnerableGNOME
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*9.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*10.0VulnerableRed Hat
  • cpe:2.3:a:gnome:libsoup:*:*:*:*:*:*:*:* Versions before 3.7.3 Vulnerable ·GNOME
  • cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Red Hat

Remediation

Red Hat 2 advisories

  • RHSA-2026:93583 Released 2026-11-02 · Red Hat rating Important
    libsoup3 security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) libsoup3-3.6.5-3.el10_0.19, libsoup3-devel-3.6.5-3.el10_0.19
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libsoup3-doc-3.6.5-3.el10_0.19
  • RHSA-2026:83618 Released 2026-10-15 · Red Hat rating Important
    libsoup3 security update
    • Red Hat Enterprise Linux AppStream (v. 10) libsoup3-3.6.5-3.el10_2.20, libsoup3-devel-3.6.5-3.el10_2.20
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libsoup3-doc-3.6.5-3.el10_2.20

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 4 more products — RHSA-2026:83618

    6 records Highest priority Priority MEDIUM 6 MEDIUM

    Other records, highest priority first

    • TI-2026-65425 Libsoup: libsoup: heap buffer overflow during outgoing permessage-deflate buffer growthPriority MEDIUM 49
    • TI-2026-65424 Libsoup: libsoup: heap buffer overflow during websocket client-frame maskingPriority MEDIUM 44
    • TI-2026-65423 Libsoup: libsoup: heap buffer overflow during websocket receive-buffer growthPriority MEDIUM 44
    Show all 6 records → Advisory →
  • Advisory ·

    Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 4 more products — RHSA-2026:93583

    6 records Highest priority Priority MEDIUM 6 MEDIUM

    Other records, highest priority first

    • TI-2026-65425 Libsoup: libsoup: heap buffer overflow during outgoing permessage-deflate buffer growthPriority MEDIUM 49
    • TI-2026-65424 Libsoup: libsoup: heap buffer overflow during websocket client-frame maskingPriority MEDIUM 44
    • TI-2026-65423 Libsoup: libsoup: heap buffer overflow during websocket receive-buffer growthPriority MEDIUM 44
    Show all 6 records → Advisory →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:83618
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:93583
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:83618
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:93583
Not affected: 2 products
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-102555
  2. 2026-10-03 Alias added: GHSA-vfxx-hcqj-vrh4
  3. 2026-10-16 Fix available: libsoup3@0:3.6.5-3.el10_2.20 · CNA
  4. 2026-10-16 1 new reference · CNA
  5. 2026-10-16 Fix available: RHSA-2026:83618 · Red Hat
  6. 2026-10-16 Fix available: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · Red Hat
  7. 2026-11-02 Fix available: libsoup3@0:3.6.5-3.el10_0.19 · CNA
  8. 2026-11-02 1 new reference · CNA
  9. 2026-11-02 Fix available: RHSA-2026:93583 · Red Hat
  10. 2026-11-02 Fix available: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) · Red Hat

References

Advisory 4

  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-10530 Code injection in [UNKNOWN] RichFaces KEVCVSS 3.1CRITICAL 9.8
  • TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
  • TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-23530 Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf… KEVCVSS 3.1CRITICAL 9.3
  • TI-2021-17490 mod_proxy SSRF KEVCVSS 3.1CRITICAL 9.0
See all 1955 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences