CVE-2026-5598: Non-constant time comparisons risk private key leakage in FrodoKEM.

Awaiting analysis

AliasesRHSA-2026:12267UBUNTU-CVE-2026-5598DEBIAN-CVE-2026-5598+289 more

Published 15-04-2026Last modified 18-09-2026

Vulnerability summary

CVE-2026-5598 is a high (CVSS 8.9) Covert Timing Channel vulnerability in legion of the bouncy castle inc. bc-java. EPSS estimates a 0.90% chance of exploitation in the next 30 days, higher than 59.6% of scored vulnerabilities.

Priority

Prioritisesevere

Severe, CVSS 8.9 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?

CVSS score

8.9/10

010

High · v4.0 (CVE.org)

EPSS score

0.90%

0%100%

Low · -0.06 pp in 30 days

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 6 · Related 2

OPENSUSE-SU-2026:10571-1 RHSA-2026:18054 RHSA-2026:18055 RHSA-2026:53644 RHSA-2026:53645 RHSA-2026:53646+1 more

Timeline

15-04-2026
PublishedVulnerability first disclosed.
18-09-2026
Last modifiedVulnerability information updated.

Description

Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules). This vulnerability is associated with program files FrodoEngine.Java. This issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.81.1, from 1.82 before 1.84.

CVSS metrics

11 scores · 8 sources · 2 versions

v4.08.9v3.17.5

EPSS trend

Probability

0.90%

Chance of exploitation in the next 30 days

Percentile

60%

Versus all other CVEs

30-day change

Decrease -0.06 pp

From 0.96% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs

CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

CWE-385Covert Timing ChannelCovert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information.

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard106 products

apache-hop< 2.17.0-r9
apache-nifi< 2.9.0-r0 | < 2.9.0-r3
apache-pulsar-4.0< 4.0.10-r0
apache-pulsar-4.1< 4.1.3-r14
apache-pulsar-4.2< 4.2.1-r0

camunda-zeebe-8.6< 8.6.39-r3
commercial-elasticsearch-8.17< 8.17.10-r2
commercial-elasticsearch-8.18All versions (No fix recorded)
commercial-elasticsearch-8.19< 8.19.15-r0
commercial-elasticsearch-9.0All versions (No fix recorded)
commercial-elasticsearch-9.1< 9.1.10-r0
commercial-elasticsearch-9.2< 9.2.8-r1
commercial-elasticsearch-9.3< 9.3.5-r0
druid< 36.0.0-r15
elasticsearch-7< 7.17.29-r12
elasticsearch-7-iamguarded< 7.17.29-r12
elasticsearch-8.17< 8.17.10-r21
elasticsearch-8.19< 8.19.14-r2
elasticsearch-8.19-iamguarded< 8.19.14-r2
elasticsearch-9.0< 9.0.8-r10
elasticsearch-9.0-iamguarded< 9.0.8-r10
elasticsearch-9.1< 9.1.10-r4
elasticsearch-9.1-iamguarded< 9.1.10-r4
elasticsearch-9.2< 9.2.8-r2
elasticsearch-9.2-iamguarded< 9.2.8-r2
elasticsearch-9.3< 9.3.3-r2
elasticsearch-9.3-iamguarded< 9.3.3-r2
geoserver-2.27< 2.27.5-r5
geoserver-2.28< 2.28.3-r3
ghidra< 12.0.4-r2
gradle-8< 8.14.4-r4
gradle-9< 9.4.1-r2
hadoop-fips-3.4.2< 3.4.2-r2
jenkins-2-openjdk-21< 2.560-r0
jenkins-2-openjdk-25< 2.560-r0
jenkins-2.528-openjdk-17< 2.528.3-r4
jenkins-2.528-openjdk-21< 2.528.3-r4
jenkins-2.541All versions (No fix recorded)
jenkins-2.541-openjdk-17All versions (No fix recorded)
jenkins-2.541-openjdk-21All versions (No fix recorded)
jenkins-2.541-openjdk-25All versions (No fix recorded)
jenkins-2.555< 2.555.2-r3
jenkins-2.555-openjdk-21< 2.555.2-r3
jenkins-2.555-openjdk-25< 2.555.2-r3
jruby-10.1< 10.1.0.0-r1
jruby-9.4< 9.4.14.0-r5
kayenta-2025.0All versions (No fix recorded)
kayenta-2025.1All versions (No fix recorded)
kayenta-2025.2< 2025.2.4-r5
kayenta-2025.4< 2025.4.3-r7
kayenta-2026.0< 2026.0.2-r7
kayenta-fips-2025.0All versions (No fix recorded)
kayenta-fips-2025.1All versions (No fix recorded)
kayenta-fips-2025.2< 2025.2.4-r6
kayenta-fips-2025.4< 2025.4.3-r8
kayenta-fips-2026.0< 2026.0.2-r8
keycloak-26.4All versions (No fix recorded)
keycloak-26.4-iamguarded-compatAll versions (No fix recorded)
keycloak-26.5All versions (No fix recorded)
keycloak-26.5-iamguarded-compatAll versions (No fix recorded)
keycloak-26.6< 26.6.1-r4
keycloak-26.6-iamguarded-compat< 26.6.1-r4
kserve-modelmesh< 0.12.0-r31
logstash-8.19< 8.19.16-r0
logstash-8.19-iamguarded-compat< 8.19.16-r0
logstash-8.19-with-output-opensearch< 8.19.16-r0
logstash-9.0All versions (No fix recorded)
logstash-9.0-iamguarded-compatAll versions (No fix recorded)
logstash-9.0-with-output-opensearchAll versions (No fix recorded)
logstash-9.1< 9.1.10-r8
logstash-9.1-bitnami-compat< 9.1.10-r8
logstash-9.1-iamguarded-compat< 9.1.10-r8
logstash-9.1-with-output-opensearch< 9.1.10-r8
logstash-9.2All versions (No fix recorded) | < 9.2.8-r4
logstash-9.2-iamguarded-compatAll versions (No fix recorded) | < 9.2.8-r4
logstash-9.2-with-output-opensearch< 9.2.8-r4 | All versions (No fix recorded)
logstash-9.3< 9.3.5-r1 | < 9.3.5-r0
logstash-9.3-iamguarded-compat< 9.3.5-r1 | < 9.3.5-r0
logstash-9.3-with-output-opensearchAll versions (No fix recorded)
logstash-9.4< 9.4.4-r0 | < 9.4.1-r3
logstash-9.4-iamguarded-compat< 9.4.1-r3 | < 9.4.4-r0
logstash-fips-9.3All versions (No fix recorded)
logstash-fips-9.3-iamguarded-compatAll versions (No fix recorded)
logstash-fips-9.4< 9.4.4-r0 | < 9.4.1-r3
logstash-fips-9.4-iamguarded-compat< 9.4.1-r3 | < 9.4.4-r0
neo4j-4.4All versions (No fix recorded)
opensearch-2-identity-shiro< 2.19.6-r0
opensearch-2-ingest-attachment< 2.19.6-r0
opensearch-2-performance-analyzer< 2.19.6-r12 | < 2.19.6-r0
opensearch-2-security< 2.19.4-r14
opensearch-2-sql< 2.19.6-r0
pinot< 1.5.0-r21
pinot-fips< 1.5.0-r11
ruby3.2-bouncy-castle-java< 1.5.0146.1-r8
ruby3.3-bouncy-castle-java< 1.5.0146.1-r6
ruby3.4-bouncy-castle-java< 1.5.0146.1-r7
ruby4.0-bouncy-castle-java< 1.5.0146.1-r3
sonarqube< 26.6.0.123539-r0
spark-4.0-scala-2.13< 4.0.2-r11
thingsboard-tb-mqtt-transport< 4.3.1.2-r0
thingsboard-tb-node< 4.3.1.2-r0
wildfly-openjdk-17< 39.0.1-r5
wildfly-openjdk-21< 39.0.1-r5
wso2is< 7.3.0-r0
zipkin< 3.6.1-r4 | < 3.6.1-r12
zipkin-slim< 3.6.1-r12 | < 3.6.1-r4

Show all 106

Wolfi34 products

apache-nifi< 2.9.0-r0 | < 2.9.0-r3
apache-pulsar-4.1< 4.1.3-r14
apache-pulsar-4.2< 4.2.1-r0
druid< 36.0.0-r15
gradle-8< 8.14.4-r4

Show all 34

Redhat6 products

eap7-bouncycastle< 0:1.84.0-1.redhat_00001.1.el7eap | < 0:1.84.0-1.redhat_00001.1.el8eap | < 0:1.84.0-1.redhat_00001.1.el9eap
eap7-bouncycastle-mail< 0:1.84.0-1.redhat_00001.1.el7eap | < 0:1.84.0-1.redhat_00001.1.el8eap | < 0:1.84.0-1.redhat_00001.1.el9eap
eap7-bouncycastle-pg< 0:1.84.0-1.redhat_00001.1.el7eap | < 0:1.84.0-1.redhat_00001.1.el8eap | < 0:1.84.0-1.redhat_00001.1.el9eap
eap7-bouncycastle-pkix< 0:1.84.0-1.redhat_00001.1.el7eap | < 0:1.84.0-1.redhat_00001.1.el8eap | < 0:1.84.0-1.redhat_00001.1.el9eap
eap7-bouncycastle-prov< 0:1.84.0-1.redhat_00001.1.el7eap | < 0:1.84.0-1.redhat_00001.1.el8eap | < 0:1.84.0-1.redhat_00001.1.el9eap

Show all 6

Org.bouncycastle3 products

bcprov-jdk14≥ 1.81, < 1.81.1
bcprov-jdk15to18≥ 1.71, < 1.80.2
bcprov-jdk18on≥ 1.82, < 1.84

Debian1 product

bouncycastleAll versions (No fix recorded) | < 1.86-1

Legion of the bouncy castle inc.1 product

bc-java≥ 1.71, < 1.80.2 | ≥ 1.81, < 1.81.1 | ≥ 1.82, < 1.84

Ubuntu1 product

bouncycastleAll versions (No fix recorded)

7 vendors · 152 products

References

30 links

github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905598Vendor AdvisoryAdvisoryWEB
github.com/bcgit/bc-java/commit/94abbd56413dfdac651fd878bc60253871ef5e87PatchFIXWEB
github.com/bcgit/bc-java/commit/8692e6b2b191fc4aafa32545c7a78bdb9bf110c5PatchFIXWEB
access.redhat.com/security/cve/CVE-2026-5598VDB EntryX Refsource REDHATREPORTAdvisory
bugzilla.redhat.com/show_bug.cgi?id=2458635Issue TrackingX Refsource REDHATREPORT
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5598.jsonX Sadp Csaf VexWEB
access.redhat.com/errata/RHSA-2026:53644Vendor AdvisoryX Refsource REDHATAdvisory
access.redhat.com/errata/RHSA-2026:12267Vendor AdvisoryX Refsource REDHATAdvisory
access.redhat.com/errata/RHSA-2026:53645Vendor AdvisoryX Refsource REDHATAdvisory
access.redhat.com/errata/RHSA-2026:18054Vendor AdvisoryX Refsource REDHATAdvisory

Show all 30 references

access.redhat.com/errata/RHSA-2026:53646Vendor AdvisoryX Refsource REDHATAdvisory
access.redhat.com/errata/RHSA-2026:18055Vendor AdvisoryX Refsource REDHATAdvisory
access.redhat.com/errata/RHSA-2026:12269Vendor AdvisoryX Refsource REDHATAdvisory
access.redhat.com/errata/RHSA-2026:18059Vendor AdvisoryX Refsource REDHATAdvisory
access.redhat.com/security/updates/classification/ARTICLE
docs.redhat.com/en/documentation/red_hat_jboss_enterprise_application_platform/7.4ARTICLE
docs.redhat.com/en/…ARTICLE
access.redhat.com/articles/7137599ARTICLE
issues.redhat.com/browse/JBEAP-32774ARTICLE
security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_12267.jsonAdvisory
www.cve.org/CVERecord?id=CVE-2026-5598AdvisoryREPORT
nvd.nist.gov/vuln/detail/CVE-2026-5598Advisory
github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905998ARTICLEREPORT
ubuntu.com/security/CVE-2026-5598REPORT
security-tracker.debian.org/tracker/CVE-2026-5598Advisory
www.bouncycastle.org/download/bouncy-castle-java/WEB
github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5598.jsonAdvisory
github.com/bcgit/bc-javaPACKAGE
access.redhat.com/errata/RHSA-2026:53806Advisory
github.com/bcgit/bc-java/wiki/CVE-2026-5598WEB