Vulnerability · CVE-2025-2817
Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior.
Published Apr 29, 2025 · catalog updated Apr 13, 2026 · Thunderbird's update mechanism allowed
Check if you run it
No confirmed exploitation is on record for CVE-2025-2817. EPSS is 0.66%. Act only if a listed version of Thunderbird's update mechanism allowed is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Thunderbird's update mechanism allowed).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High8.8
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.66%
- Remediation
- Advisory link
- Affected products
- vendor mozilla
Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Thunderbird 138, and Thunderbird 128.10.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor mozillaversion unspecified
How to fix CVE-2025-2817
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2025-2817. EPSS is 0.66%. Act only if a listed version of Thunderbird's update mechanism allowed is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.66%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Apr 29, 2025 · EUVD
Detected
Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability was
Apr 13, 2026 · EUVD
Updated
Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability was
Sources
- CVE.orgVulnerability recordCVE-2025-2817
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2025-2817
30-day exploitation probability 0.7%
first.org - EUVDVulnerability recordEUVD-2025-12689
Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-leve
euvd.enisa.europa.eu
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.