glib-networking TLS client: unbounded session ticket growth exhausts memory
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-400.
Summary
glib-networking in Red Hat Enterprise Linux 9 and Red Hat Enterprise Linux 10 is affected. The client-side TLS 1.3 session cache does not limit the number of session tickets it keeps for a single host, an uncontrolled resource consumption flaw (CWE-400). A malicious remote server can send excessive session ticket messages without authentication, making the client application consume memory until system memory is exhausted and service is denied.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
A flaw was found in glib-networking. When establishing connections using Transport Layer Security (TLS) version 1.3, the client-side session cache does not limit the number of session tickets retained for a single host. A malicious server can exploit this by sending excessive session ticket messages, causing the client application to continuously consume memory. This unbounded memory growth can exhaust system memory, resulting in a Denial of Service (DoS).
Why it matters now
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected 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
Remediation
The sources list no fixed version for Red Hat Enterprise Linux 9. The sources list no fixed version for Red Hat Enterprise Linux 10. Red Hat lists no fix plan for Red Hat Enterprise Linux 9 or 10. Red Hat lists Red Hat Enterprise Linux 6, 7 and 8 as not affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-30 Threatist record created from CVE-2026-103963
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 CVSS score added · Red Hat
- 2026-10-30 Alias added: GHSA-xwh2-f88c-v27r
- 2026-10-31 Priority changed: MEDIUM → LOW
- 2026-11-04 CISA SSVC decision points changed
References
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Sources
- CVE-2026-103963 · CVE Program
- CVE-2026-103963 · NVD
- FIRST EPSS
- GHSA-xwh2-f88c-v27r · GitHub Advisory Database · CC BY 4.0
- CVE-2026-103963 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences