CVE catalog
CVE-2025-49600
mbedtls: CVE-2025-49600
- Severity
- Medium · CVSS 4.9
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.16% · Oct 25, 2026
In MbedTLS 3.3.0 before 3.6.4, mbedtls_lms_verify may accept invalid signatures if hash computation fails and internal errors go unchecked, enabling LMS (Leighton-Micali Signature) forgery in a fault scenario. Specifically, unchecked return values in mbedtls_lms_verify allow an attacker (who can induce a hardware hash accelerator fault) to bypass LMS signature verification by reusing stale stack data, resulting in acceptance of an invalid signature. In mbedtls_lms_verify, the return values of the internal Merkle tree functions create_merkle_leaf_value and create_merkle_internal_value are not checked. These functions return an integer that indicates whether the call succeeded or not. If a failure occurs, the output buffer (Tc_candidate_root_node) may remain uninitialized, and the result of the signature verification is unpredictable. When the software implementation of SHA-256 is used, these functions will not fail. However, with hardware-accelerated hashing, an attacker could use fault injection against the accelerator to bypass verification.
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 | mbedtls | sid | 3.6.7-3 | fixed |
| Debian | mbedtls | forky | 3.6.7-3 | fixed |
| Debian | mbedtls | trixie | 3.6.6-0.1~deb13u1 | fixed |
| Debian | mbedtls | bookworm | 2.28.3-1 | not affected |
| Alpine | mbedtls | 3.20 | 3.6.4-r0 | fixed |
| Alpine | mbedtls | 3.21 | 3.6.4-r0 | fixed |
| Alpine | mbedtls | 3.22 | 3.6.4-r0 | fixed |
| Alpine | mbedtls | 3.23 | 3.6.4-r0 | fixed |
| Alpine | mbedtls | 3.24 | 3.6.4-r0 | fixed |
| Ubuntu | mbedtls | 25.10 | 3.6.2-3ubuntu1 | vulnerable |
| Ubuntu | mbedtls | 26.04 | 3.6.2-3ubuntu1 | vulnerable |
| Ubuntu | mbedtls | 26.04 | 3.6.5-0.1ubuntu1 | vulnerable |
| Ubuntu | mbedtls | 26.04 | 3.6.5-0.1ubuntu2 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | mbedtls | source | sid | 3.6.4-1 | not yet assigned | Not reported | [1108787] |
| Debian | mbedtls | source | forky | 3.6.4-1 | not yet assigned | Not reported | [1108787] |
| Debian | mbedtls | source | trixie | 3.6.4-1 | not yet assigned | Not reported | [1108787] |
| Debian | mbedtls | source | bookworm | Not affected | unimportant | Not reported | [1108787] |
| Alpine | mbedtls | apk | 3.20 | 3.6.4-r0 | Not reported | ALPINE-CVE-2025-49600 | Not reported |
| Alpine | mbedtls | apk | 3.21 | 3.6.4-r0 | Not reported | ALPINE-CVE-2025-49600 | Not reported |
| Alpine | mbedtls | apk | 3.22 | 3.6.4-r0 | Not reported | ALPINE-CVE-2025-49600 | Not reported |
| Alpine | mbedtls | apk | 3.23 | 3.6.4-r0 | Not reported | ALPINE-CVE-2025-49600 | Not reported |
| Alpine | mbedtls | apk | 3.24 | 3.6.4-r0 | Not reported | ALPINE-CVE-2025-49600 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libmbedcrypto7]Not affected
Source package: [mbedtls]
Details (2)
2.28.3-1· amd64 · bookwormNot affected
dsa · mbedtls · debian · bookworm
2.28.3-1· arm64 · bookwormNot affected
dsa · mbedtls · debian · bookworm
- [libmbedtls14]Not affected
Source package: [mbedtls]
Details (2)
2.28.3-1· amd64 · bookwormNot affected
dsa · mbedtls · debian · bookworm
2.28.3-1· arm64 · bookwormNot affected
dsa · mbedtls · debian · bookworm
- [libmbedtls-dev]Not affected
Source package: [mbedtls]
Details (2)
2.28.3-1· amd64 · bookwormNot affected
dsa · mbedtls · debian · bookworm
2.28.3-1· arm64 · bookwormNot affected
dsa · mbedtls · debian · bookworm
- [libmbedtls-doc]Not affected
Source package: [mbedtls]
Details (2)
2.28.3-1· all · bookwormNot affected
dsa · mbedtls · debian · bookworm
2.28.3-1· all · bookwormNot affected
dsa · mbedtls · debian · bookworm
- [libmbedx509-1]Not affected
Source package: [mbedtls]
Details (2)
2.28.3-1· amd64 · bookwormNot affected
dsa · mbedtls · debian · bookworm
2.28.3-1· arm64 · bookwormNot affected
dsa · mbedtls · debian · bookworm
[Debian 13 (Trixie)]
- [libmbedcrypto16]Fixed
Source package: [mbedtls]
Details (2)
3.6.5-0.1~deb13u1· amd64 · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
3.6.5-0.1~deb13u1· arm64 · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
- [libmbedtls21]Fixed
Source package: [mbedtls]
Details (2)
3.6.5-0.1~deb13u1· amd64 · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
3.6.5-0.1~deb13u1· arm64 · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
- [libmbedtls-dev]Fixed
Source package: [mbedtls]
Details (2)
3.6.5-0.1~deb13u1· amd64 · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
3.6.5-0.1~deb13u1· arm64 · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
- [libmbedtls-doc]Fixed
Source package: [mbedtls]
Details (2)
3.6.5-0.1~deb13u1· all · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
3.6.5-0.1~deb13u1· all · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
- [libmbedx509-7]Fixed
Source package: [mbedtls]
Details (2)
3.6.5-0.1~deb13u1· amd64 · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
3.6.5-0.1~deb13u1· arm64 · trixieFixed · Fixed:
3.6.4-1dsa · mbedtls · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_21144-1.json]
- [https://osv.dev/vulnerability/ALPINE-CVE-2025-49600]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2025-49600]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2025-49600]
- [https://security-tracker.debian.org/tracker/CVE-2025-49600]
- [https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-49600.json]
[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]