Security readout for executives and security teams
Plain-English summary
CVE-2026-2443 is a memory disclosure flaw in libsoup, an HTTP library used on GNOME-based Linux systems. A remote attacker may be able to read small portions of server heap memory by sending crafted HTTP Range headers, but only where an application exposes the embedded SoupServer component in a vulnerable configuration.
Executive priority
Treat as a moderate-priority confidentiality issue. It is remotely reachable in the right application configuration, but current public sources show no active exploitation and no code execution impact. Prioritize internet-facing SoupServer use cases and follow vendor patch guidance.
Technical view
The issue is a CWE-125 out-of-bounds read in libsoup’s handle_partial_get() Range header handling. Improper byte-range validation can cause unintended heap data to be included beyond the intended response. Red Hat lists libsoup/libsoup3 packages across RHEL 6, 7, 8, 9, and 10 as affected. CVSS is 5.3: network, low complexity, no privileges, confidentiality impact only.
Likely exposure
Exposure is most likely in server-side applications using libsoup’s embedded SoupServer to serve HTTP responses and accepting external requests. Systems with libsoup installed but not using SoupServer in a reachable service may have limited practical exposure. Confirm application-level use, not just package presence.
Exploitation context
The provided sources do not indicate active exploitation, and the CVE is not marked KEV. Exploitation requires network access to a service using the vulnerable SoupServer behavior and crafted Range headers. Impact is limited to information disclosure; no integrity or availability impact is stated.
Researcher notes
Evidence points to Range header parsing in handle_partial_get() and possible heap information disclosure. The main uncertainty is deployment-specific exposure: libsoup may be installed broadly, while vulnerable reachability depends on SoupServer usage. Public sources provided do not include exploit details or confirmed fixed versions.
Mitigation direction
- Inventory RHEL systems with libsoup or libsoup3 installed.
- Identify applications exposing libsoup SoupServer to untrusted networks.
- Check Red Hat and GNOME advisories for fixed package availability.
- Prioritize updates where SoupServer is externally reachable.
- Restrict network access to affected services where updates are unavailable.
Validation and detection
- Confirm installed libsoup or libsoup3 package versions on affected RHEL systems.
- Map running services to applications using the libsoup SoupServer component.
- Review vendor advisories for exact fixed versions and errata.
- Verify vulnerable services are not exposed unnecessarily.
- Document systems where package presence does not imply reachable SoupServer usage.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-125: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-2443 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://access.redhat.com/security/cve/CVE-2026-2443CVE reference · vdb-entry, x_refsource_REDHAT
- RHBZ#2439671CVE reference · issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/487CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.