CVE-Katalog
CVE-2026-54876
Issue summary: A malicious TLS server can cause a memory leak in a TLS client that has enabled OCSP response checking by sending an OCSP response that contains no single response entries. Impact summ
- Schweregrad
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.52% · Oct 22, 2026
Issue summary: A malicious TLS server can cause a memory leak in a TLS client that has enabled OCSP response checking by sending an OCSP response that contains no single response entries. Impact summary: An attacker can leak an attacker-tunable amount of memory per TLS handshake in a victim client application. A long-running client that repeatedly connects to a malicious server can have its memory exhausted, resulting in a Denial of Service. CWE: CWE-401: Missing Release of Memory after Effective Lifetime Description: The affected function is called during X.509 certificate chain verification when OCSP response checking is enabled with the X509_V_FLAG_OCSP_RESP_CHECK or X509_V_FLAG_OCSP_RESP_CHECK_ALL verification flags, for example when a TLS client verifies an OCSP response stapled into the TLS handshake by the server. When the received BasicOCSPResponse contains an empty SEQUENCE OF SingleResponse, which is permitted on the wire and accepted by the OpenSSL decoder, the OCSP_BASICRESP structure allocated by OCSP_response_get1_basic() was not freed because an early return bypassed the cleanup code at the end of the function. The amount of memory leaked per handshake can be amplified by the attacker by padding the certs field of the BasicOCSPResponse with bogus certificates, which are parsed and stored in the leaked structure before the empty response check triggers the early return. A long-running TLS client that repeatedly connects to a malicious server can have its memory exhausted over time. OCSP response checking is not enabled by default. Only client applications that explicitly enable the OCSP response check verification flags are affected. FIPS impact: no The FIPS modules in 4.0 and 3.6 are not affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | openssl | sid | 3.6.5-1 | fixed |
| Debian | openssl | forky | 3.6.5-1 | fixed |
| Debian | openssl | trixie | 3.5.7-1~deb13u2 | not affected |
| Debian | openssl | trixie-security | 3.5.7-1~deb13u3 | not affected |
| Debian | openssl | bookworm | 3.0.20-1~deb12u2 | not affected |
| Debian | openssl | bookworm-security | 3.0.22-1~deb12u1 | not affected |
| Ubuntu | nodejs | pro | 6.11.4~dfsg-1ubuntu1 | vulnerable |
| Ubuntu | nodejs | pro | 6.11.4~dfsg-1ubuntu2 | vulnerable |
| Ubuntu | nodejs | pro | 6.12.0~dfsg-1ubuntu1 | vulnerable |
| Ubuntu | nodejs | pro | 6.12.0~dfsg-2ubuntu1 | vulnerable |
| Ubuntu | nodejs | pro | 6.12.0~dfsg-2ubuntu2 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2ubuntu0.2 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2ubuntu0.3 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2ubuntu0.4 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2ubuntu0.4+esm1 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2ubuntu0.4+esm2 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2ubuntu0.4+esm3 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2ubuntu0.4+esm4 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2ubuntu0.4+esm5 | vulnerable |
| Ubuntu | nodejs | pro | 8.10.0~dfsg-2ubuntu0.4+esm6 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | openssl | source | sid | 3.6.4-1 | not yet assigned | Not reported | [1143841] |
| Debian | openssl | source | forky | 3.6.4-1 | not yet assigned | Not reported | [1143841] |
| Debian | openssl | source | trixie | Not affected | unimportant | Not reported | [1143841] |
| Debian | openssl | source | bookworm | Not affected | unimportant | Not reported | [1143841] |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libssl3]Nicht betroffen
Quellpaket: [openssl]
Details (6)
3.0.20-1~deb12u2· amd64 · bookwormNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· arm64 · bookwormNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· amd64 · bookworm-securityNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· arm64 · bookworm-securityNicht betroffen
nvd · openssl · debian · bookworm
3.0.17-1~deb12u2· amd64 · bookworm-updatesNicht betroffen
nvd · openssl · debian · bookworm
3.0.17-1~deb12u2· arm64 · bookworm-updatesNicht betroffen
nvd · openssl · debian · bookworm
- [libssl-dev]Nicht betroffen
Quellpaket: [openssl]
Details (6)
3.0.20-1~deb12u2· amd64 · bookwormNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· arm64 · bookwormNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· amd64 · bookworm-securityNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· arm64 · bookworm-securityNicht betroffen
nvd · openssl · debian · bookworm
3.0.17-1~deb12u2· amd64 · bookworm-updatesNicht betroffen
nvd · openssl · debian · bookworm
3.0.17-1~deb12u2· arm64 · bookworm-updatesNicht betroffen
nvd · openssl · debian · bookworm
- [libssl-doc]Nicht betroffen
Quellpaket: [openssl]
Details (6)
3.0.20-1~deb12u2· all · bookwormNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· all · bookwormNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· all · bookworm-securityNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· all · bookworm-securityNicht betroffen
nvd · openssl · debian · bookworm
3.0.17-1~deb12u2· all · bookworm-updatesNicht betroffen
nvd · openssl · debian · bookworm
3.0.17-1~deb12u2· all · bookworm-updatesNicht betroffen
nvd · openssl · debian · bookworm
- [openssl]Nicht betroffen
Details (6)
3.0.20-1~deb12u2· amd64 · bookwormNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· arm64 · bookwormNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· amd64 · bookworm-securityNicht betroffen
nvd · openssl · debian · bookworm
3.0.20-1~deb12u2· arm64 · bookworm-securityNicht betroffen
nvd · openssl · debian · bookworm
3.0.17-1~deb12u2· amd64 · bookworm-updatesNicht betroffen
nvd · openssl · debian · bookworm
3.0.17-1~deb12u2· arm64 · bookworm-updatesNicht betroffen
nvd · openssl · debian · bookworm
Beobachtet:
Referenzen
- [https://access.redhat.com/errata/RHSA-2026:56097]
- [https://ftp.suse.com/pub/projects/security/]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-54876]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-54876]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-54876]
- [https://security-tracker.debian.org/tracker/CVE-2026-54876]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2668.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]