8.6

CVE-2026-110249: thunderbird Uncontrolled Resource Consumption

CVSS: 8.6v3.1HighAwaiting analysis
AliasesDEBIAN-CVE-2026-110249UBUNTU-CVE-2026-110249
Published 13-10-2026Last modified 20-10-2026
Open JSON

Vulnerability summary

CVE-2026-110249 is a high (CVSS 8.6) Uncontrolled Resource Consumption vulnerability in thunderbird. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 6.1% of scored vulnerabilities.

Overall risk
34/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.6/10
010
High · v3.1 (CVE.org)
EPSS score
0.17%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 1
MGASA-2026-0523SUSE-SU-2026:4736-1

Timeline

  1. 13-10-2026
    PublishedVulnerability first disclosed.
  2. 20-10-2026
    Last modifiedVulnerability information updated.

Description

A malicious, compromised, or MITM-controlled Exchange server can return a single well-formed SOAP response containing an element with enough attributes to keep Thunderbird's main thread CPU-bound for seconds to hours. This vulnerability was fixed in Thunderbird 158 and Thunderbird 153.5.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

6%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

14-10-202620-10-2026
EPSS score
0.17%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • thunderbirdAll versions (No fix recorded)
Ubuntu1 product
  • thunderbirdAll versions (No fix recorded)

2 vendors · 2 products

References

7 links