8.1

CVE-2026-77762: apache software foundation apache tomcat Race Condition

CVSS: 8.1v3.1HighAwaiting analysis
AliasesUBUNTU-CVE-2026-77762DEBIAN-CVE-2026-77762
Published 23-09-2026Last modified 30-09-2026
Open JSON

Vulnerability summary

CVE-2026-77762 is a high (CVSS 8.1) Race Condition vulnerability in apache software foundation apache tomcat. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.2% of scored vulnerabilities.

Overall risk
32/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.36%
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 10 · Related 7
MGASA-2026-0479OPENSUSE-SU-2026:11906-1OPENSUSE-SU-2026:11907-1OPENSUSE-SU-2026:11908-1OPENSUSE-SU-2026:21984-1RHSA-2026:68257

Timeline

  1. 23-09-2026
    PublishedVulnerability first disclosed.
  2. 30-09-2026
    Last modifiedVulnerability information updated.

Description

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.39 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fix the issue.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.36%

Chance of exploitation in the next 30 days

Percentile

28%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

24-09-202618-10-2026
EPSS score
0.36%

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

Ubuntu6 products
  • tomcat10All versions (No fix recorded)
  • tomcat11All versions (No fix recorded)
  • tomcat6All versions (No fix recorded)
  • tomcat7All versions (No fix recorded)
  • tomcat8All versions (No fix recorded)
Debian3 products
  • tomcat10All versions (No fix recorded) | < 10.1.60-1
  • tomcat11All versions (No fix recorded)
  • tomcat9< 9.0.70-2
Apache software foundation1 product
  • apache tomcat≥ 11.0.0-M1, ≤ 11.0.25 | ≥ 10.1.0-M1, ≤ 10.1.59 | ≥ 9.0.39, ≤ 9.0.121 | ≥ 8.5.59, ≤ 8.5.100

3 vendors · 10 products

References

8 links