CVE-2026-35189: Excessive Memory Allocation in Relative CRLDP Processing
Noroxi assessment
Priority: Monitor (action score 21/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.31% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: OpenSSL OpenSSL 3.0.23, 3.4.8, 3.5.9; azl3 edk2 20240524git3e722403cd16-20 on Azure Linux 3.0 20240524git3e722403cd16-21; azl3 openssl 3.3.7-6 on Azure Linux 3.0 3.3.7-7.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to OpenSSL OpenSSL 3.0.23, 3.4.8, 3.5.9; azl3 edk2 20240524git3e722403cd16-20 on Azure Linux 3.0 20240524git3e722403cd16-21; azl3 openssl 3.3.7-6 on Azure Linux 3.0 3.3.7-7 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Issue summary: A certificate with many nameRelativeToCRLIssuer CRL distribution points causes disproportionate heap growth when OpenSSL caches X.509 extensions. Impact summary: Receiving a crafted certificate from a malicious peer can lead to significant memory pressure and possible Denial of Service in clients or in servers that solicit client certificates. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: A certificate or a set of certificates that fits under the limit for size of certificates accepted from the peer (~100 KiB) can result in allocation of several hundred MiB of resident memory on the receiving side during a normal TLS handshake. This may be enough to crash the client or server, if multiple concurrent connections lead to similarly large memory allocations. The fix postpones processing of the CRL distribution points extensions in certificates to the time when the processed value is required for CRL processing. This avoids keeping large memory allocations for a long time when such certificates are received. FIPS impact: no The affected code is outside the FIPS module boundary.
- Published
- Sep 29, 2026
- Updated
- Oct 8, 2026
- EPSS
- 0.3% · 24th percentile
- CWE
- CWE-770
Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| openssl | openssl | cpe:2.3:a:openssl:openssl |
Check your server's TLS configuration
The OpenSSL version can't be seen from outside; the free SSL checker tests your certificate, enabled TLS versions and weak ciphers. Confirm the version on your server with the package manager.
Run the SSL checkAffected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- openssl openssl1.0.2 and later · before 1.0.2zs
- openssl openssl1.1.1 and later · before 1.1.1zj
- openssl openssl3.0.0 and later · before 3.0.23
- openssl openssl3.4.0 and later · before 3.4.8
- openssl openssl3.5.0 and later · before 3.5.9
- openssl openssl3.6.0 and later · before 3.6.5
- openssl openssl4.0.0 and later · before 4.0.3
Versions reported by the vendor
Affected version ranges reported by the assigning authority (openssl). Independent of NVD's CPE analysis and usually ahead of it.
OpenSSL OpenSSL
- 4.0.0 and later · before 4.0.3affected · semver
- 3.6.0 and later · before 3.6.5affected · semver
- 3.5.0 and later · before 3.5.9affected · semver
- 3.4.0 and later · before 3.4.8affected · semver
- 3.0.0 and later · before 3.0.23affected · semver
- 1.1.1 and later · before 1.1.1zjaffected
- 1.0.2 and later · before 1.0.2zsaffected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.21 | openssl | from 1.0.2 · before 3.3.7-r2 | 3.3.7-r2 |
| Debian:12 | openssl | before 3.0.22-1~deb12u2 | 3.0.22-1~deb12u2 |
| Debian:13 | openssl | before 3.5.7-1~deb13u3 | 3.5.7-1~deb13u3 |
| Debian:14 | openssl | before 3.6.5-1 | 3.6.5-1 |
| openSUSE:Leap 16.0 | openssl-3 | before 3.5.0-160000.11.1 | 3.5.0-160000.11.1 |
| Red Hat:hummingbird:1 | openssl | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl-config-fips | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl-devel | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl-devel-engine | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl-fips-provider-upstream | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl-libs | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl-perl | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl3 | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl3-devel | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl3-devel-engine | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| Red Hat:hummingbird:1 | openssl3-libs | before 0:3.5.9-0.1.hum1 | 0:3.5.9-0.1.hum1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | openssl-3 | before 3.0.8-150500.5.80.1 | 3.0.8-150500.5.80.1 |
| SUSE:Linux Enterprise Micro 5.3 | openssl-3 | before 3.0.8-150400.4.101.1 | 3.0.8-150400.4.101.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | openssl-3 | before 3.5.0-150700.5.53.2 | 3.5.0-150700.5.53.2 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | openssl-3 | before 3.1.4-150600.5.67.1 | 3.1.4-150600.5.67.1 |
| SUSE:Linux Micro 6.0 | openssl-3 | before 3.1.4-159998.1.1 | 3.1.4-159998.1.1 |
| SUSE:Linux Micro 6.1 | openssl-3 | before 3.1.4-slfo.1.1_14.1 | 3.1.4-slfo.1.1_14.1 |
| SUSE:Linux Micro 6.2 | openssl-3 | before 3.5.0-160000.11.1 | 3.5.0-160000.11.1 |
Same product
openssl: all recordsOther highest-scoring records for the same primary product.
- CVE-2014-0160The (1) TLS and (2) DTLS implementations in OpenSSL 1.0.1 before 1.0.1g do not properly handle Heartbeat Extension packets, which allows remKEV90Now
- CVE-2021-3711SM2 Decryption Buffer Overflow65This week
- CVE-2003-0545Double free vulnerability in OpenSSL 0.9.7 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code 65This week
Published before and after this one in the same product
- ← EarlierCVE-2026-63076Aug 25, 2026 · Invalid Pointer Dereference in CMP Server via Crafted protectionAlg30Monitor
- ← EarlierCVE-2026-75803Aug 25, 2026 · AEAD Forgeries with Empty Ciphertext When Using EVP_Cipher()36Monitor
- Later →CVE-2026-35191Sep 29, 2026 · QUIC Unvalidated Amplification Credit may be Over Accounted14Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| OpenSSL OpenSSL | 3.0.23 | Vendor (CNA) |
| OpenSSL OpenSSL | 3.4.8 | Vendor (CNA) |
| OpenSSL OpenSSL | 3.5.9 | Vendor (CNA) |
| OpenSSL OpenSSL | 3.6.5 | Vendor (CNA) |
| OpenSSL OpenSSL | 4.0.3 | Vendor (CNA) |
| azl3 edk2 20240524git3e722403cd16-20 on Azure Linux 3.0 | 20240524git3e722403cd16-21 · Release Notes | Microsoft (MSRC) |
| azl3 openssl 3.3.7-6 on Azure Linux 3.0 | 3.3.7-7 · Release Notes | Microsoft (MSRC) |
| azl3 shim-unsigned-aarch64 16.1-2 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| azl3 shim-unsigned-x64 16.1-2 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| alpine:openssl | 3.3.7-r2 · Alpine:v3.21 | Package registry (OSV) |
| debian:openssl | 3.0.22-1~deb12u2 · Debian:12 | Package registry (OSV) |
| debian:openssl | 3.5.7-1~deb13u3 · Debian:13 | Package registry (OSV) |
| opensuse:openssl-3 | 3.5.0-160000.11.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| red hat:openssl | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl-config-fips | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl-devel | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl-devel-engine | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl-fips-provider-upstream | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl-libs | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl-perl | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl3 | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl3-devel | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl3-devel-engine | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl3-libs | 0:3.5.9-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| suse:openssl-3 | 3.0.8-150500.5.80.1 · SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | Package registry (OSV) |
| suse:openssl-3 | 3.1.4-159998.1.1 · SUSE:Linux Micro 6.0 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayNov 3, 2026+35 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Fuzz0x (ZKSC InstituteSecurity Research)reporter
- Viktor Dukhovniremediation developer
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-548730 days apartQUIC STREAM Fragment Metadata DoS30Monitor
- CVE-2026-847840 days apartQUIC: Unbounded RETIRE_CONNECTION_ID Backlog30Monitor
- CVE-2026-6307535 days apartQUIC ACK-only Packet Retention Can Cause Memory Exhaustion30Monitor
- CVE-2026-1445647 days apartUnbounded Memory Growth in QUIC Server Incoming Channel Queue30Monitor
- CVE-2026-6307435 days apartCMP Indefinite Cache Growth of ExtraCerts23Monitor
- CVE-2026-758040 days apartQUIC Connection-Level Flow Control is Not Enforced for Streams21Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1218 · Sep 30, 2026(OpenSSL Güvenlik Zafiyeti)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- Low
Weakness class (CWE)
CWE-770 · Allocation of Resources Without Limits or ThrottlingCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- FloodingCAPEC-125likelihood: High · Medium
- Excessive AllocationCAPEC-130likelihood: Medium · Medium
- XML Ping of the DeathCAPEC-147likelihood: Low · Medium
- Exponential Data ExpansionCAPEC-197likelihood: High · Medium
- Serialized Data Parameter BlowupCAPEC-229likelihood: High · High
- Serialized Data with Nested PayloadsCAPEC-230likelihood: Medium · High
- Oversized Serialized Data PayloadsCAPEC-231likelihood: Medium · High
- HTTP DoSCAPEC-469Low
ATT&CK techniques
- Network Denial of Service:Direct Network FloodT1498.001
- Network Denial of Service:Reflection AmplificationT1498.002
- Endpoint Denial of ServiceT1499
- Endpoint Denial of Service: OS Exhaustion FloodT1499.001
- Endpoint Denial of Service:Service Exhaustion FloodT1499.002
- Endpoint Denial of Service:Application Exhaustion FloodT1499.003
Change log
- CVSS— → 5.3
- Severity— → medium
- SSVC exploitation— → none
- Exploit maturity— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (4 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.