Security readout for executives and security teams
Plain-English summary
CVE-2026-1536 affects libsoup, an HTTP library used in Red Hat Enterprise Linux packages. If an attacker can control a Content-Disposition header value, they may inject extra HTTP headers. This can affect integrity of HTTP traffic, but published severity is medium and no active exploitation is cited in the provided sources.
Executive priority
Treat as a moderate-priority integrity issue. It is not currently cited as exploited, but it affects common enterprise Linux platforms and can enable header manipulation where applications pass untrusted data into HTTP headers.
Technical view
The flaw is CWE-93 CRLF injection in libsoup/libsoup3 handling of Content-Disposition header input. CRLF sequences may be interpreted verbatim during HTTP request or response construction, enabling HTTP header injection or response splitting. CVSS is 5.8, network exploitable, low complexity, no privileges or user interaction, changed scope, low integrity impact.
Likely exposure
Exposure is most likely where RHEL 6, 7, 8, 9, or 10 systems use libsoup or libsoup3 in applications that place attacker-controlled data into Content-Disposition headers.
Exploitation context
Sources state exploitation requires attacker control of Content-Disposition header input and does not require authentication or user interaction. There is no KEV listing and no cited evidence of active exploitation in the provided bundle.
Researcher notes
Evidence is limited to the CVE description, Red Hat affected-product metadata, Bugzilla, and GNOME issue references. The bundle does not name fixed versions, patches, or proof-of-concept details. Avoid assuming all libsoup-using applications are exploitable; input control over Content-Disposition is key.
Mitigation direction
- Check Red Hat and GNOME/libsoup advisories for fixed package availability and upgrade guidance.
- Inventory RHEL systems with libsoup or libsoup3 installed.
- Review applications that build Content-Disposition headers using untrusted input.
- Reject or sanitize carriage return and line feed characters in header values.
- Prioritize internet-facing services that process attacker-supplied filenames or download metadata.
Validation and detection
- Confirm installed libsoup or libsoup3 package versions across RHEL assets.
- Identify services or applications linked against libsoup.
- Review code paths that set Content-Disposition from user-controlled data.
- Monitor vendor references for status changes, errata, or backported fixes.
- Check logs for suspicious header anomalies, without treating absence as proof of safety.
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-93: Exact CWE lookup
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Open ATT&CK lookupCVE-2026-1536 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
- 5.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/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:C/C:N/I:L/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.8MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://access.redhat.com/security/cve/CVE-2026-1536CVE reference · vdb-entry, x_refsource_REDHAT
- RHBZ#2433834CVE reference · issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/486CVE 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.
Improper Neutralization of CRLF Sequences ('CRLF Injection')
Improper Neutralization of CRLF Sequences ('CRLF Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.