CVE-2026-41898 | rust-openssl: Unchecked callback-returned length in PSK and cookie generate trampolines can cause OpenSSL to leak adjacent memory to the network peer

rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.9.24 to before 0.10.78, the FFI trampolines behind SslContextBuilder::set_psk_client_callback, set_psk_server_callback, set_cookie_generate_cb, and set_stateless_cookie_generate_cb forwarded the user closure's returned usize directly to OpenSSL without checking it against the &mut [u8] that was handed to the closure. This can lead to buffer overflows and other unintended consequences. This vulnerability is fixed in 0.10.78.

Published: 2026-04-24 Last update: 2026-04-27 Assigner: [email protected] Source: [email protected]
NVD Status：Undergoing Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-41898 is rated Low Risk (39.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-41898

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-30 0.04% 0.06% +0.01%
2 2026-04-25 — 0.04% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-41898

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.3 4.0 HIGH
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/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:X Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:P)
Additional preconditions must be present for exploitation.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:H)
High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:L)
Limited availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:X)
Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
 — — [email protected]

Weakness enumeration for CVE-2026-41898

GitHub Security Advisory for CVE-2026-41898

GHSA-hppc-g8h3-xhp3 · Severity: high · Ecosystem: rust — rust-openssl: Unchecked callback length in PSK/cookie trampolines leaks adjacent memory to peer

OS Trackers for CVE-2026-41898

vendor priority summary link
debian not yet assigned CVE-2026-41898 not yet assigned priority: Debian including 1 source packages (rust-openssl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-41898
ubuntu medium CVE-2026-41898 medium priority: Ubuntu including 1 source packages (rust-openssl), 6 status rows across 6 suites (focal, jammy, noble, questing, resolute, upstream): needs-triage 5, released 1. https://ubuntu.com/security/CVE-2026-41898

Affected software / configurations for CVE-2026-41898

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-41898

cvelogic Threat Intelligence