CVE-2025-32910: Libsoup: null pointer deference on libsoup via /auth/soup-auth-digest.c through "soup_auth_digest_authenticate" on client when server omits the "realm" parameter in an unauthorized response with digest authentication
A flaw was found in libsoup, where soup_auth_digest_authenticate() is vulnerable to a NULL pointer dereference. This issue may cause the libsoup client to crash.
Security readout for executives and security teams
Plain-English summary
This is a crash bug in libsoup, an HTTP client library. A server response missing a Digest authentication value can make an affected client application terminate. The main business impact is availability: affected applications may crash when they contact a problematic or malicious service.
Executive priority
Treat as a moderate availability issue. Patch through normal vulnerability management, faster for client systems or services that contact untrusted HTTP endpoints. It does not indicate data theft or privilege escalation in the provided sources.
Technical view
libsoup's soup_auth_digest_authenticate() can hit a NULL pointer dereference when processing a Digest authentication unauthorized response that omits the realm parameter. The CVSS vector is network-reachable with low complexity, no privileges, user interaction required, and high availability impact only.
Likely exposure
Exposure is most likely in applications using affected libsoup client code. The bundle identifies Red Hat Enterprise Linux 9 libsoup as affected, RHEL 8 listed packages as affected, RHEL 10 libsoup3 as unaffected, and RHEL 6/7 status as unknown.
Exploitation context
The source bundle does not show CISA KEV listing or any cited claim of active exploitation. Practical impact is denial of service against a client application after it processes a malformed Digest authentication response.
Researcher notes
The affected condition is specific: Digest authentication handling when the unauthorized response lacks realm. Keep validation focused on package status, linked applications, and vendor patches. Do not assume exploit activity or broader product impact beyond the cited affected entries.
Mitigation direction
Apply Red Hat fixes from RHSA-2025:8292 where applicable.
Review Debian LTS guidance for affected Debian deployments.
Inventory applications that use libsoup for HTTP client requests.
Prioritize clients that contact untrusted or user-controlled HTTP services.
Check vendor advisories for unsupported or unknown-status platforms.
Validation and detection
Confirm installed libsoup or vendor package versions against advisories.
Identify applications linking to or bundling libsoup.
Review crash reports for NULL dereference patterns in Digest authentication handling.
Verify patched systems no longer report vulnerable package versions.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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cwe · low confidence lookup
CWE-476: Exact CWE lookup
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CWE-476 · source CWE mapping
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.