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TI-2025-00197 Aliases CVE-2025-0239GHSA-p4q7-g7ff-823j

Alt-Svc ALPN validation failure when redirected

Priority LOW 18CWE-295Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Spoofing
Confidentiality · integrity · availability
None · Low · None
Fix status
Partial Red Hat: 14 fixed, 4 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-295.

Summary

When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00227 13th percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 128.6, 134Thunderbird (Mozilla): 128.6, 134Red Hat: 19 advisoriesRed Hat: 14 fixed, 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefox—128.6, 134Patch availableCNA
MozillaThunderbird—128.6, 134Patch availableCNA
  • Firefox VendorMozilla Affected — Fixed in 128.6, 134 Patch available CNA
  • Thunderbird VendorMozilla Affected — Fixed in 128.6, 134 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*before 128.6.0VulnerableMozilla
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 134.0VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*before 128.6.0; 129.0 to before 134.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* Versions before 128.6.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 134.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 128.6.0; 129.0 to before 134.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 128.6, 134
  • Fix · CNA Thunderbird (Mozilla) Fixed in 128.6, 134

Red Hat 19 advisories

  • RHSA-2025:0286 Released 2025-01-13 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v. 8.2) thunderbird-128.6.0-3.el8_2
  • RHSA-2025:0287 Released 2025-01-13 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird-128.6.0-3.el8_4
    • Red Hat Enterprise Linux AppStream E4S (v.8.4) thunderbird-128.6.0-3.el8_4
    • Red Hat Enterprise Linux AppStream TUS (v.8.4) thunderbird-128.6.0-3.el8_4
  • RHSA-2025:0284 Released 2025-01-13 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.8.8) thunderbird-128.6.0-3.el8_8
Show 16 more Red Hat advisories
  • RHSA-2025:0281 Released 2025-01-13 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 8) thunderbird-128.6.0-3.el8_10
  • RHSA-2025:0275 Released 2025-01-13 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) thunderbird-128.6.0-3.el8_6
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) thunderbird-128.6.0-3.el8_6
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) thunderbird-128.6.0-3.el8_6
  • RHSA-2025:0167 Released 2025-01-09 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.2) thunderbird-128.6.0-3.el9_2
  • RHSA-2025:0166 Released 2025-01-09 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) thunderbird-128.6.0-3.el9_4
  • RHSA-2025:0165 Released 2025-01-09 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) thunderbird-128.6.0-3.el9_0
  • RHSA-2025:0162 Released 2025-01-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox-128.6.0-1.el9_0
  • RHSA-2025:0144 Released 2025-01-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 8) firefox-128.6.0-1.el8_10
  • RHSA-2025:0147 Released 2025-01-09 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 9) thunderbird-128.6.0-3.el9_5
  • RHSA-2025:0137 Released 2025-01-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.8.8) firefox-128.6.0-1.el8_8
  • RHSA-2025:0138 Released 2025-01-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.2) firefox-128.6.0-1.el9_2, firefox-x11-128.6.0-1.el9_2
  • RHSA-2025:0136 Released 2025-01-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox-128.6.0-1.el8_6
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox-128.6.0-1.el8_6
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox-128.6.0-1.el8_6
  • RHSA-2025:0132 Released 2025-01-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) firefox-128.6.0-1.el7_9
  • RHSA-2025:0135 Released 2025-01-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) firefox-128.6.0-1.el9_4, firefox-x11-128.6.0-1.el9_4
  • RHSA-2025:0134 Released 2025-01-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-128.6.0-1.el8_4
    • Red Hat Enterprise Linux AppStream E4S (v.8.4) firefox-128.6.0-1.el8_4
    • Red Hat Enterprise Linux AppStream TUS (v.8.4) firefox-128.6.0-1.el8_4
  • RHSA-2025:0133 Released 2025-01-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v. 8.2) firefox-128.6.0-1.el8_2
  • RHSA-2025:0080 Released 2025-01-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 9) firefox-128.6.0-1.el9_5, firefox-x11-128.6.0-1.el9_5

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2025:0144, RHSA-2025:0281
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2025:0080, RHSA-2025:0147
Red Hat Enterprise Linux AppStream AUS (v. 8.2)Fixed RHSA-2025:0133, RHSA-2025:0286
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2025:0134, RHSA-2025:0287
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2025:0136, RHSA-2025:0275
Red Hat Enterprise Linux AppStream E4S (v.8.4)Fixed RHSA-2025:0134, RHSA-2025:0287
Red Hat Enterprise Linux AppStream E4S (v.8.6)Fixed RHSA-2025:0136, RHSA-2025:0275
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2025:0162, RHSA-2025:0165
Red Hat Enterprise Linux AppStream EUS (v.8.8)Fixed RHSA-2025:0137, RHSA-2025:0284
Red Hat Enterprise Linux AppStream EUS (v.9.2)Fixed RHSA-2025:0138, RHSA-2025:0167
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2025:0135, RHSA-2025:0166
Red Hat Enterprise Linux AppStream TUS (v.8.4)Fixed RHSA-2025:0134, RHSA-2025:0287
Red Hat Enterprise Linux AppStream TUS (v.8.6)Fixed RHSA-2025:0136, RHSA-2025:0275
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2025:0132

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-0239
  2. 2026-10-03 Alias added: GHSA-p4q7-g7ff-823j

References

Advisory 4

Other 1

  • TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
  • TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
  • TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
  • TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
See all 3444 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences