Leak of hashed Window credentials via crafted attachment URL
Noroxi assessment
Priority: Monitor (action score 25/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.27% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
- Fixed version: thunderbird (AlmaLinux:10) 128.10.0-1.el10_0.alma.1; thunderbird (AlmaLinux:8) 128.9.2-1.el8_10.alma.1; thunderbird (AlmaLinux:9) 128.10.0-1.el9_6.alma.1, 128.9.2-1.el9_5.alma.1.
Low priority for now. Upgrade to thunderbird (AlmaLinux:10) 128.10.0-1.el10_0.alma.1; thunderbird (AlmaLinux:8) 128.9.2-1.el8_10.alma.1; thunderbird (AlmaLinux:9) 128.10.0-1.el9_6.alma.1, 128.9.2-1.el9_5.alma.1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Thunderbird processes the X-Mozilla-External-Attachment-URL header to handle attachments which can be hosted externally. When an email is opened, Thunderbird accesses the specified URL to determine file size, and navigates to it when the user clicks the attachment. Because the URL is not validated or sanitized, it can reference internal resources like chrome:// or SMB share file:// links, potentially leading to hashed Windows credential leakage and opening the door to more serious security issues. This vulnerability was fixed in Thunderbird 137.0.2 and Thunderbird 128.9.2.
- BDU:2025-06555
- ALSA-2025:4229
- ALSA-2025:4649
- ALSA-2025:7435
- ALSA-2025:7507
- DLA-4167-1
- DSA-5912-1
- openSUSE-SU-2025:15000-1
- RHSA-2025:4229
- RHSA-2025:4389
- RHSA-2025:4512
- RHSA-2025:4513
- RHSA-2025:4514
- RHSA-2025:4617
- RHSA-2025:4649
- RHSA-2025:4654
- RHSA-2025:4665
- RHSA-2025:7435
- RHSA-2025:7507
- RLSA-2025:7435
- Published
- Apr 15, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.2% · 18th percentile
- CWE
- CWE-601
Report tools
Action score
25
Monitor
Low priority for now.
- CVSS
- 25 / 40 · 6.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Running WordPress? Scan your site free with WP Lens
Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| mozilla | thunderbird | cpe:2.3:a:mozilla:thunderbird |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- mozilla thunderbirdbefore 128.9.2
- mozilla thunderbird129.0 and later · before 137.0.2
Versions reported by the vendor
Affected version ranges reported by the assigning authority (mozilla). Independent of NVD's CPE analysis and usually ahead of it.
Mozilla Thunderbird
- 128.9.2 and later · up to and including 128.*not affected · rpm
- 137.0.2 and laternot affected · rpm
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | thunderbird | before 128.10.0-1.el10_0.alma.1 | 128.10.0-1.el10_0.alma.1 |
| AlmaLinux:8 | thunderbird | before 128.9.2-1.el8_10.alma.1 | 128.9.2-1.el8_10.alma.1 |
| AlmaLinux:9 | thunderbird | before 128.10.0-1.el9_6.alma.1 | 128.10.0-1.el9_6.alma.1 |
| AlmaLinux:9 | thunderbird | before 128.9.2-1.el9_5.alma.1 | 128.9.2-1.el9_5.alma.1 |
| Debian:11 | thunderbird | before 1:128.10.1esr-1~deb11u1 | 1:128.10.1esr-1~deb11u1 |
| Debian:12 | thunderbird | before 1:128.10.0esr-1~deb12u1 | 1:128.10.0esr-1~deb12u1 |
| Debian:13 | thunderbird | before 1:128.10.0esr-1 | 1:128.10.0esr-1 |
| openSUSE:Tumbleweed | MozillaThunderbird | before 128.9.2-1.1 | 128.9.2-1.1 |
| Red Hat:enterprise_linux:10.0 | thunderbird | before 0:128.10.0-1.el10_0 | 0:128.10.0-1.el10_0 |
| Red Hat:enterprise_linux:10.0 | thunderbird-debuginfo | before 0:128.10.0-1.el10_0 | 0:128.10.0-1.el10_0 |
| Red Hat:enterprise_linux:10.0 | thunderbird-debugsource | before 0:128.10.0-1.el10_0 | 0:128.10.0-1.el10_0 |
| Red Hat:enterprise_linux:8::appstream | thunderbird | before 0:128.9.2-1.el8_10 | 0:128.9.2-1.el8_10 |
| Red Hat:enterprise_linux:8::appstream | thunderbird-debuginfo | before 0:128.9.2-1.el8_10 | 0:128.9.2-1.el8_10 |
| Red Hat:enterprise_linux:8::appstream | thunderbird-debugsource | before 0:128.9.2-1.el8_10 | 0:128.9.2-1.el8_10 |
| Red Hat:enterprise_linux:9::appstream | thunderbird | before 0:128.10.0-1.el9_6 | 0:128.10.0-1.el9_6 |
| Red Hat:enterprise_linux:9::appstream | thunderbird | before 0:128.9.2-1.el9_5 | 0:128.9.2-1.el9_5 |
| Red Hat:enterprise_linux:9::appstream | thunderbird-debuginfo | before 0:128.10.0-1.el9_6 | 0:128.10.0-1.el9_6 |
| Red Hat:enterprise_linux:9::appstream | thunderbird-debuginfo | before 0:128.9.2-1.el9_5 | 0:128.9.2-1.el9_5 |
| Red Hat:enterprise_linux:9::appstream | thunderbird-debugsource | before 0:128.9.2-1.el9_5 | 0:128.9.2-1.el9_5 |
| Red Hat:enterprise_linux:9::appstream | thunderbird-debugsource | before 0:128.10.0-1.el9_6 | 0:128.10.0-1.el9_6 |
| Red Hat:rhel_aus:8.2::appstream | thunderbird | before 0:128.9.2-1.el8_2 | 0:128.9.2-1.el8_2 |
| Red Hat:rhel_aus:8.2::appstream | thunderbird-debuginfo | before 0:128.9.2-1.el8_2 | 0:128.9.2-1.el8_2 |
| Red Hat:rhel_aus:8.2::appstream | thunderbird-debugsource | before 0:128.9.2-1.el8_2 | 0:128.9.2-1.el8_2 |
| Red Hat:rhel_aus:8.4::appstream | thunderbird | before 0:128.9.2-1.el8_4 | 0:128.9.2-1.el8_4 |
+20
Same product
mozilla: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-11705A flaw in Thunderbird's implementation of iCal causes a stack buffer overflow in icalrecur_add_bydayrules when processing certain email mess42Plan
- CVE-2019-11704A flaw in Thunderbird's implementation of iCal causes a heap buffer overflow in icalmemory_strdup_and_dequote when processing certain email 42Plan
- CVE-2019-11703A flaw in Thunderbird's implementation of iCal causes a heap buffer overflow in parser_get_next_char when processing certain email messages,42Plan
Published before and after this one in the same product
- ← EarlierCVE-2025-26696Mar 10, 2025 · Crafted email message incorrectly shown as being encrypted28Monitor
- ← EarlierCVE-2025-2830Apr 15, 2025 · Information Disclosure of /tmp directory listing25Monitor
- Later →CVE-2025-3523Apr 15, 2025 · User Interface (UI) Misrepresentation of attachment URL25Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:thunderbird | 128.9.2-1.el9_5.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| debian:thunderbird | 1:128.10.0esr-1~deb12u1 · Debian:12 | Package registry (OSV) |
| opensuse:MozillaThunderbird | 128.9.2-150200.8.209.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| red hat:thunderbird | 0:128.9.2-1.el9_5 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:thunderbird-debuginfo | 0:128.9.2-1.el9_5 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:thunderbird-debugsource | 0:128.9.2-1.el9_5 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| rocky linux:thunderbird | 0:128.10.0-1.el9_5 · Rocky Linux:9 | Package registry (OSV) |
| suse:MozillaThunderbird | 128.9.2-150200.8.209.1 · SUSE:Linux Enterprise Module for Package Hub 15 SP6 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- Low
Weakness class (CWE)
CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.