NSS 3.124 Release

[John Schanck]

Network Security Services (NSS) 3.124 was released on 15 May 2026.

The HG tag is NSS_3_124_RTM. This version of NSS requires NSPR 4.38.2 or newer. The latest version of NSPR is 4.39.

NSS 3.124 source distributions are available on ftp.mozilla.org for secure HTTPS download:

<https://ftp.mozilla.org/pub/security/nss/releases/NSS_3_124_RTM/src/>

Changes:
    Bug 2032562 - Add test for PKCS7 digest array alignment.
    Bug 2030093 - Add test for rejection of excessively large ASN.1 SEQUENCE OF in quickder.
    Bug 2030994 - Add test for CMS content size validation.
    Bug 2030995 - Add regression tests for DSAU signature decoding.
    Bug 2031030 - Add test for S/MIME profile lookup on temp certs.
    Bug 2031343 - Test case for post-handshake auth and many certificate requests.
    Bug 2019233 - Add test for intra-arena ASan redzones.
    Bug 2033058 - update nss_status flags one at a time.
    Bug 2029803 - add defensive info->len check in PK11_HPKE_SetupS and PK11_HPKE_SetupR.
    Bug 2029403 - avoid PORT_Strdup in ssl_DecodeResumptionToken.
    Bug 2020596 - add runtime check on decoded resumption token session id.
    Bug 2035882 - improve mach try error handling.
    Bug 2030798 - clang format.
    Bug 2030798 - add comprehensive SECItem and SECItemArray tests.
    Bug 2033058 - add bugzilla_cf_status_nss.py script.
    Bug 2033057 - regenerate some recent release notes.
    Bug 2033057 - fix bug list output by release note and email scripts.
    Bug 2031190 - test removal from trust domain email cache.
    Bug 2033208 - fix "testing if key corruption is detected in attribute" failures with sqlite-3.53.0.
    Bug 2035348 - build sqlite3 shell for Windows CI runners.
    Bug 2030366 - avoid race with module unloading in NSSTrustDomain_FindTokensByURI.
    Bug 2030192 - add ImportEd25519WithNonEmptyAlgorithmParams test.
    Bug 2034258 - add CLAUDE.md and .mcp.json.
    Bug 2034244 - add a mach try command.
    Bug 2031042 - remove dead condition in sec_asn1d_check_and_subtract_length.
    Bug 2030374 - avoid integer truncation in nssCKObject_GetAttributes.
    Bug 2030564 - add defensive input validation to sftk_compute_ANSI_X9_63_kdf.
    Bug 2029765 - avoid refcount over-release in nssTokenObjectCache error path [@ nssToken_Destroy].
    Bug 2029883 - sdb: enforce that metaData's id key is unique when reading.
    Bug 2023478 - improve handling of escape sequences in pk11uri_ParseAttributes.
    Bug 2030570 - use correct data for ID comparison in transfer_uri_certs_to_collection.
    Bug 2030573 - fix truncation of ulValueLen in sdb_FindObjectsInit.
    Bug 2033783 - reject DTLS 1.3 Server Hello after HVR without capping ss->vrange.max.
    Bug 2034157 - set previous-nss-release for abicheck.
    Bug 2032389 - Skip `PR_Sleep` yield for non-blocking sockets in `ssl3_SendApplicationData`.
    Bug 2033650 - consistently protect PK11SlotInfo::maxKeyCount with freeListLock.
    Bug 2030985 - Remove CRMF from testing and manifests.
    Bug 2026711 - Remove unused RSA blind signature implementation from freebl.

NSS 3.124 shared libraries are backwards-compatible with all older NSS 3.x shared libraries. A program linked with older NSS 3.x shared libraries will work with this new version of the shared libraries without recompiling or relinking. Furthermore, applications that restrict their use of NSS APIs to the functions listed in NSS Public Functions will remain compatible with future versions of the NSS shared libraries.

Bugs discovered should be reported by filing a bug report at <https://bugzilla.mozilla.org/enter_bug.cgi?product=NSS>

Release notes are available at <https://firefox-source-docs.mozilla.org/security/nss/releases/index.html>.