Advisory details:
vulnrichment / CVE-2026-34477
| Advisory ID | vulnrichment/CVE-2026-34477 |
| Aliases | |
| Summary | The fix for CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName system property, but not when configured through the verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName attribute of the <Ssl> element. Although the verifyHostName configuration attribute was introduced in Log4j Core 2.12.0, it was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception regardless of the configured value. A network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met: * An SMTP, Socket, or Syslog appender is in use. * TLS is configured via a nested <Ssl> element. * The attacker can present a certificate issued by a CA trusted by the appender's configured trust store, or by the default Java trust store if none is configured. This issue does not affect users of the HTTP appender, which uses a separate verifyHostname https://logging.apache.org/log4j/2.x/manual/appenders/network.html#HttpAppender-attr-verifyHostName attribute that was not subject to this bug and verifies host names by default. Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue. |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 0.0 |
| Risk | |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| System | Score | Found at |
|---|---|---|
| cvssv4 | 6.3 | |
| ssvc | Track |
| Reference id | Reference type | URL |
|---|---|---|
| https://logging.apache.org/cyclonedx/vdr.xml | ||
| https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName | ||
| 4075 | Other | https://github.com/apache/logging-log4j2/pull/4075 |
| cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:* | https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:* | |
| lkx8cl46t2bvkcwfcb2pd43ygc097lq4 | Advisory | https://lists.apache.org/thread/lkx8cl46t2bvkcwfcb2pd43ygc097lq4 |
| security.html#CVE-2026-34477 | Advisory | https://logging.apache.org/security.html#CVE-2026-34477 |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Attack Requirements (AT) | Privileges Required (PR) | User Interaction (UI) | Vulnerable System Impact Confidentiality (VC) | Vulnerable System Impact Integrity (VI) | Vulnerable System Impact Availability (VA) | Subsequent System Impact Confidentiality (SC) | Subsequent System Impact Integrity (SI) | Subsequent System Impact Availability (SA) |
|---|---|---|---|---|---|---|---|---|---|---|
network adjacent local physical |
low high |
none present |
none low high |
none passive active |
high low none |
high low none |
high low none |
high low none |
high low none |
high low none |
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2026-04-10T17:36:46Z/
Decision: Track
Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/34xxx/CVE-2026-34477.json
Source Advisory: vulnrichment/CVE-2026-34477
[{'Exploitation': 'none'},
{'Automatable': 'no'},
{'Technical Impact': 'partial'},
{'Mission Prevalence': 'minimal'},
{'Public Well-being Impact': 'material'},
{'Mission & Well-being': 'medium'}]