Skip to content
Noroxi
NVD / CVE Program· CNA mozilla

CVE-2025-3523: User Interface (UI) Misrepresentation of 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: 0.31% (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. Special conditions such as timing or configuration are required.
  • 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) 128.9.2-1.el9_5.alma.1, 128.10.0-1.el9_6.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) 128.9.2-1.el9_5.alma.1, 128.10.0-1.el9_6.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

When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct link is used on click, the misleading hover text could trick users into downloading content from untrusted sources. This vulnerability was fixed in Thunderbird 137.0.2 and Thunderbird 128.9.2.

MediumCVSS 6.4 · v3.1—No exploit Fix available
Published
Apr 15, 2025
Updated
Jun 17, 2026
EPSS
0.3% · 24th percentile

Report tools

JSON

Action score

25

Monitor

Low priority for now.

CVSS
25 / 40 · 6.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

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.

Follow CVE-2025-3523

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for mozilla records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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 help

Affected 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.

VendorProduct
mozillathunderbird

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.

EcosystemPackageAffected rangeFix
AlmaLinux:10thunderbirdbefore 128.10.0-1.el10_0.alma.1128.10.0-1.el10_0.alma.1
AlmaLinux:8thunderbirdbefore 128.9.2-1.el8_10.alma.1128.9.2-1.el8_10.alma.1
AlmaLinux:9thunderbirdbefore 128.9.2-1.el9_5.alma.1128.9.2-1.el9_5.alma.1
AlmaLinux:9thunderbirdbefore 128.10.0-1.el9_6.alma.1128.10.0-1.el9_6.alma.1
Debian:11thunderbirdbefore 1:128.10.1esr-1~deb11u11:128.10.1esr-1~deb11u1
Debian:12thunderbirdbefore 1:128.10.0esr-1~deb12u11:128.10.0esr-1~deb12u1
Debian:13thunderbirdbefore 1:128.10.0esr-11:128.10.0esr-1
openSUSE:Leap 15.6MozillaThunderbirdbefore 128.9.2-150200.8.209.1128.9.2-150200.8.209.1
openSUSE:TumbleweedMozillaThunderbirdbefore 128.9.2-1.1128.9.2-1.1
Red Hat:enterprise_linux:10.0thunderbirdbefore 0:128.10.0-1.el10_00:128.10.0-1.el10_0
Red Hat:enterprise_linux:10.0thunderbird-debuginfobefore 0:128.10.0-1.el10_00:128.10.0-1.el10_0
Red Hat:enterprise_linux:10.0thunderbird-debugsourcebefore 0:128.10.0-1.el10_00:128.10.0-1.el10_0
Red Hat:enterprise_linux:8::appstreamthunderbirdbefore 0:128.9.2-1.el8_100:128.9.2-1.el8_10
Red Hat:enterprise_linux:8::appstreamthunderbird-debuginfobefore 0:128.9.2-1.el8_100:128.9.2-1.el8_10
Red Hat:enterprise_linux:8::appstreamthunderbird-debugsourcebefore 0:128.9.2-1.el8_100:128.9.2-1.el8_10
Red Hat:enterprise_linux:9::appstreamthunderbirdbefore 0:128.9.2-1.el9_50:128.9.2-1.el9_5
Red Hat:enterprise_linux:9::appstreamthunderbirdbefore 0:128.10.0-1.el9_60:128.10.0-1.el9_6
Red Hat:enterprise_linux:9::appstreamthunderbird-debuginfobefore 0:128.9.2-1.el9_50:128.9.2-1.el9_5
Red Hat:enterprise_linux:9::appstreamthunderbird-debuginfobefore 0:128.10.0-1.el9_60:128.10.0-1.el9_6
Red Hat:enterprise_linux:9::appstreamthunderbird-debugsourcebefore 0:128.9.2-1.el9_50:128.9.2-1.el9_5
Red Hat:enterprise_linux:9::appstreamthunderbird-debugsourcebefore 0:128.10.0-1.el9_60:128.10.0-1.el9_6
Red Hat:rhel_aus:8.2::appstreamthunderbirdbefore 0:128.9.2-1.el8_20:128.9.2-1.el8_2
Red Hat:rhel_aus:8.2::appstreamthunderbird-debuginfobefore 0:128.9.2-1.el8_20:128.9.2-1.el8_2
Red Hat:rhel_aus:8.2::appstreamthunderbird-debugsourcebefore 0:128.9.2-1.el8_20:128.9.2-1.el8_2

+20

Same product

mozilla: all records

Other 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 mess
    42Plan
  • 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-2025-2830Apr 15, 2025 · Information Disclosure of /tmp directory listing
    25Monitor
  • ← EarlierCVE-2025-3522Apr 15, 2025 · Leak of hashed Window credentials via crafted attachment URL
    25Monitor
  • Later →CVE-2025-3875May 14, 2025 · Sender Spoofing via Malformed From Header in Thunderbird
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:thunderbird128.9.2-1.el9_5.alma.1 · AlmaLinux:9Package registry (OSV)
debian:thunderbird1:128.10.0esr-1~deb12u1 · Debian:12Package registry (OSV)
opensuse:MozillaThunderbird128.9.2-150200.8.209.1 · openSUSE:Leap 15.6Package registry (OSV)
red hat:thunderbird0:128.9.2-1.el9_5 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:thunderbird-debuginfo0:128.9.2-1.el9_5 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:thunderbird-debugsource0:128.9.2-1.el9_5 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
rocky linux:thunderbird0:128.10.0-1.el9_5 · Rocky Linux:9Package registry (OSV)
suse:MozillaThunderbird128.9.2-150200.8.209.1 · SUSE:Linux Enterprise Module for Package Hub 15 SP6Package 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.

EPSS, last 120 days

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 researchers

Finders, 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.

  • CVE-2025-598657 days apartUnsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links
    26Monitor
  • CVE-2026-3889343 days apartSpoofing issue in Thunderbird
    26Monitor

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.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
low · data can be read
Integrity
high · data or configuration can be modified
Availability
low · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
High
Availability impact
Low

Weakness class (CWE)

CWE-451 · User Interface (UI) Misrepresentation of Critical Information

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/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.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records