CVE-2026-63568

highpriority · track · 30EPSS 0.003 · 25 %ileDEUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.32% (25th) EPSS

CVSS 7.5 · high

Is it mine?

13 products

Check your exposure

Who says so?

2 sources

cert_bund · nvd

EPSS · scored 2026-10-27

Allocation of resources without limits or throttling in the CMP/CRMF password-based MAC verifier (PKMacBuilder) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote unauthenticated attacker to cause a denial of service through CPU exhaustion via a CMP message or CRMF certificate request whose PBMParameter declares a very large iteration count, because PKMacBuilder enforced its iteration-count ceiling only when the caller had supplied an explicit maximum through the PKMacBuilder(IPKMacPrimitivesProvider, int) constructor. With any other constructor, ProtectedPkiMessage.Verify and CertificateRequestMessage.IsValidSigningKeyPop performed as many hash iterations as the sender requested, up to about 2^31, before the MAC could be checked.

cvss

Technical severity, 0–10. One row per scoring source.

8.7

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v4.08.7highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary

v4.06.6mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-770US

affected products (13)

Products and version ranges known to be affected.

Open Source Bouncy Castle bc-csharp <2.7.0all versionscert_bundDE
Open Source Bouncy Castle for Java <1.86all versionscert_bundDE
Open Source Bouncy Castle for Java FIPS <1.0.13all versionscert_bundDE
Open Source Bouncy Castle for Java FIPS <2.0.13all versionscert_bundDE
Open Source Bouncy Castle for Java FIPS <2.1.13all versionscert_bundDE
Open Source Bouncy Castle for Java LTS <2.73.13all versionscert_bundDE
Open Source Bouncy Castle≤ bc-csharp <2.7.0cert_bundDE
Open Source Bouncy Castle≤ for Java <1.86cert_bundDE
Open Source Bouncy Castle≤ for Java FIPS <1.0.13cert_bundDE
Open Source Bouncy Castle≤ for Java FIPS <2.0.13cert_bundDE
Open Source Bouncy Castle≤ for Java FIPS <2.1.13cert_bundDE
Open Source Bouncy Castle≤ for Java LTS <2.73.13cert_bundDE
bouncycastle bc-csharp< 2.7.0nvdUScpe:2.3:a:bouncycastle:bc-csharp:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-3713Bouncy Castle: Mehrere SchwachstellenDeutsch2026-10-01csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Bouncy Castle ausnutzen, um Sicherheitsvorkehrungen zu umgehen, Daten zu manipulieren oder offenzulegen und einen Denial-of-Service-Zustand auszulösen.

sources

Which sources assert this record, and when.

cert_bund nvd NVD CVE.org MITRE

published 2026-10-02modified 2026-10-27

references (4) nvd

External citations — patches, advisories, analysis.

scry

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