CVE-2026-2443: Libsoup: out-of-bounds read in libsoup handle_partial_get leading to heap information disclosure

Medium [CVE-2026-12549 +1] Libsoup: incomplete fix for CVE-2026-2443: range suffix overflow in libsoup soupserver

CVE-2026-12549Source published Jun 22, 2026Source updated Apr 24, 2024

This bulletin covers 2 CVEs. The products, versions, score and guidance below describe the bulletin; check its source for applicability to this specific CVE.

The fix for CVE-2026-2443 was regressed by a subsequent rework commit that replaced specific overflow checks with a general signed comparison. When a client sends a Range request with a suffix length exceeding the content size, the resulting negative start value is not properly clamped, leading to malformed HTTP 206 responses and log flooding. This vulnerability is rated Moderate for Red Hat because it requires a non-default configuration where max_incoming_payload_size is explicitly set to 0 or unset in libsoup's WebSocket frame processing. In typical Red Hat deployments, this configuration is not enabled by default, limiting the exposure to memory disclosure or application instability. Red Hat severity: Moderate — CVSS 4.8 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L). Weakness…

Affected products in this advisory

• Red Hat Enterprise Linux 10
• Red Hat Enterprise Linux 6
• Red Hat Enterprise Linux 7
• Red Hat Enterprise Linux 8

2 more entries in the full advisory.

Source-reported affected versions

Affected-version details not available in this record.

Source-reported fixed versions

No fixed-version detail extracted. This does not mean no fix exists.

Mitigation guidance

• To mitigate this issue, applications utilizing libsoup's WebSocket support should ensure that the `max_incoming_payload_size` is explicitly set to a non-zero value. This prevents the library from processing WebSocket frames with an unset or zero maximum payload size, which can lead to out-of-bounds reads. Consult application-specific documentation for configuring libsoup parameters.

Medium [CVE-2026-2443] Libsoup: out-of-bounds read in libsoup handle_partial_get leading to heap information disclosure

CVE-2026-2443Source published Feb 13, 2026Source updated Feb 13, 2026

A flaw was identified in libsoup, a widely used HTTP library in GNOME-based systems. When processing specially crafted HTTP Range headers, the library may improperly validate requested byte ranges. In certain build configurations, this could allow a remote attacker to access portions of server memory beyond the intended response. Exploitation requires a vulnerable configuration and access to a server using the embedded SoupServer component. This issue has a LOW impact. An out-of-bounds read vulnerability in libsoup, when processing HTTP Range headers, can lead to heap information disclosure. Although upstream exploitation may allow disclosure of heap memory contents, Red Hat does not build GLib with G_DISABLE_CHECKS, which prevents creation of out-of-bounds byte slices in supported…

Affected products in this advisory

• Red Hat Enterprise Linux 10
• Red Hat Enterprise Linux 6
• Red Hat Enterprise Linux 7
• Red Hat Enterprise Linux 8

2 more entries in the full advisory.

Source-reported affected versions

Affected-version details not available in this record.

Source-reported fixed versions

No fixed-version detail extracted. This does not mean no fix exists.

Mitigation guidance

• Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.