Django REST framework

Vulnerability Instance

Lookup for vulnerabilities affecting packages.

Vulnerability_idVCID-6u4f-wt5u-8ueb
Summarygnutls: Incorrect certificate validation when using OCSP responses (GNUTLS-SA-2016-3)
Aliases
0
alias CVE-2016-7444
Fixed_packages
0
url pkg:alpm/archlinux/gnutls@3.4.15-1
purl pkg:alpm/archlinux/gnutls@3.4.15-1
is_vulnerable false
affected_by_vulnerabilities
resource_url http://public2.vulnerablecode.io/packages/pkg:alpm/archlinux/gnutls@3.4.15-1
1
url pkg:alpm/archlinux/lib32-gnutls@3.4.15-1
purl pkg:alpm/archlinux/lib32-gnutls@3.4.15-1
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-k31b-6m7s-pffq
resource_url http://public2.vulnerablecode.io/packages/pkg:alpm/archlinux/lib32-gnutls@3.4.15-1
2
url pkg:apk/alpine/gnutls@3.4.5-r1?arch=armhf&distroversion=v3.2&reponame=main
purl pkg:apk/alpine/gnutls@3.4.5-r1?arch=armhf&distroversion=v3.2&reponame=main
is_vulnerable false
affected_by_vulnerabilities
resource_url http://public2.vulnerablecode.io/packages/pkg:apk/alpine/gnutls@3.4.5-r1%3Farch=armhf&distroversion=v3.2&reponame=main
3
url pkg:apk/alpine/gnutls@3.4.5-r1?arch=x86&distroversion=v3.2&reponame=main
purl pkg:apk/alpine/gnutls@3.4.5-r1?arch=x86&distroversion=v3.2&reponame=main
is_vulnerable false
affected_by_vulnerabilities
resource_url http://public2.vulnerablecode.io/packages/pkg:apk/alpine/gnutls@3.4.5-r1%3Farch=x86&distroversion=v3.2&reponame=main
4
url pkg:apk/alpine/gnutls@3.4.5-r1?arch=x86_64&distroversion=v3.2&reponame=main
purl pkg:apk/alpine/gnutls@3.4.5-r1?arch=x86_64&distroversion=v3.2&reponame=main
is_vulnerable false
affected_by_vulnerabilities
resource_url http://public2.vulnerablecode.io/packages/pkg:apk/alpine/gnutls@3.4.5-r1%3Farch=x86_64&distroversion=v3.2&reponame=main
5
url pkg:deb/debian/gnutls28@3.5.3-4?distro=trixie
purl pkg:deb/debian/gnutls28@3.5.3-4?distro=trixie
is_vulnerable false
affected_by_vulnerabilities
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.5.3-4%3Fdistro=trixie
6
url pkg:deb/debian/gnutls28@3.5.8-5%2Bdeb9u5
purl pkg:deb/debian/gnutls28@3.5.8-5%2Bdeb9u5
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-3qcs-1fcj-m3fw
1
vulnerability VCID-6fzu-8998-abdk
2
vulnerability VCID-86j1-j381-cucy
3
vulnerability VCID-92x9-x1ep-cqdn
4
vulnerability VCID-9pdw-udwq-6kbz
5
vulnerability VCID-a18u-4j99-nbf8
6
vulnerability VCID-a296-a2f2-kfba
7
vulnerability VCID-abn3-2b4q-z7ga
8
vulnerability VCID-f5c7-jcd9-67hj
9
vulnerability VCID-gy9e-81rw-pug2
10
vulnerability VCID-jxjc-vjdc-1yfj
11
vulnerability VCID-k31b-6m7s-pffq
12
vulnerability VCID-k5vv-ts4z-j7g5
13
vulnerability VCID-pf5n-65mk-2ff3
14
vulnerability VCID-q3g5-4xaf-hudf
15
vulnerability VCID-qp8x-339r-pbhe
16
vulnerability VCID-qtsh-kn2d-h7cr
17
vulnerability VCID-r531-qbtt-akgf
18
vulnerability VCID-sp9u-9wwg-b7e9
19
vulnerability VCID-uc8j-r79v-n7ck
20
vulnerability VCID-uws5-j79f-cbar
21
vulnerability VCID-vz27-wyaf-tkcr
22
vulnerability VCID-w7f6-5b6h-8kh4
23
vulnerability VCID-wqyp-93bk-vbh2
24
vulnerability VCID-x5jd-qddc-eudq
25
vulnerability VCID-zjx8-ydmt-juf3
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.5.8-5%252Bdeb9u5
7
url pkg:deb/debian/gnutls28@3.7.1-5%2Bdeb11u5?distro=trixie
purl pkg:deb/debian/gnutls28@3.7.1-5%2Bdeb11u5?distro=trixie
is_vulnerable false
affected_by_vulnerabilities
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.7.1-5%252Bdeb11u5%3Fdistro=trixie
8
url pkg:deb/debian/gnutls28@3.7.9-2%2Bdeb12u5?distro=trixie
purl pkg:deb/debian/gnutls28@3.7.9-2%2Bdeb12u5?distro=trixie
is_vulnerable false
affected_by_vulnerabilities
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.7.9-2%252Bdeb12u5%3Fdistro=trixie
9
url pkg:deb/debian/gnutls28@3.8.9-3%2Bdeb13u2?distro=trixie
purl pkg:deb/debian/gnutls28@3.8.9-3%2Bdeb13u2?distro=trixie
is_vulnerable false
affected_by_vulnerabilities
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.8.9-3%252Bdeb13u2%3Fdistro=trixie
10
url pkg:deb/debian/gnutls28@3.8.12-3?distro=trixie
purl pkg:deb/debian/gnutls28@3.8.12-3?distro=trixie
is_vulnerable false
affected_by_vulnerabilities
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.8.12-3%3Fdistro=trixie
Affected_packages
0
url pkg:alpm/archlinux/gnutls@3.4.14-1
purl pkg:alpm/archlinux/gnutls@3.4.14-1
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-6u4f-wt5u-8ueb
resource_url http://public2.vulnerablecode.io/packages/pkg:alpm/archlinux/gnutls@3.4.14-1
1
url pkg:alpm/archlinux/lib32-gnutls@3.4.14-1
purl pkg:alpm/archlinux/lib32-gnutls@3.4.14-1
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-6u4f-wt5u-8ueb
resource_url http://public2.vulnerablecode.io/packages/pkg:alpm/archlinux/lib32-gnutls@3.4.14-1
2
url pkg:deb/debian/gnutls28@3.2.15-1~bpo70%2B1
purl pkg:deb/debian/gnutls28@3.2.15-1~bpo70%2B1
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-334s-gdq8-jucy
1
vulnerability VCID-3qcs-1fcj-m3fw
2
vulnerability VCID-4f3z-x697-abd5
3
vulnerability VCID-5aea-cjz1-jkh1
4
vulnerability VCID-6fzu-8998-abdk
5
vulnerability VCID-6u4f-wt5u-8ueb
6
vulnerability VCID-86j1-j381-cucy
7
vulnerability VCID-92x9-x1ep-cqdn
8
vulnerability VCID-9pdw-udwq-6kbz
9
vulnerability VCID-a18u-4j99-nbf8
10
vulnerability VCID-a296-a2f2-kfba
11
vulnerability VCID-abn3-2b4q-z7ga
12
vulnerability VCID-egeh-jk4m-sba8
13
vulnerability VCID-f5c7-jcd9-67hj
14
vulnerability VCID-fybd-zwbt-23ad
15
vulnerability VCID-gy9e-81rw-pug2
16
vulnerability VCID-hycu-7x87-jkcf
17
vulnerability VCID-jxjc-vjdc-1yfj
18
vulnerability VCID-k31b-6m7s-pffq
19
vulnerability VCID-k5vv-ts4z-j7g5
20
vulnerability VCID-m31f-a3pn-yyb4
21
vulnerability VCID-mtvm-zj2z-m7gf
22
vulnerability VCID-nce1-q8wc-s3ae
23
vulnerability VCID-p6yt-pz69-xkd8
24
vulnerability VCID-pf5n-65mk-2ff3
25
vulnerability VCID-q3g5-4xaf-hudf
26
vulnerability VCID-qp8x-339r-pbhe
27
vulnerability VCID-qtsh-kn2d-h7cr
28
vulnerability VCID-qup9-qy11-fqhe
29
vulnerability VCID-r531-qbtt-akgf
30
vulnerability VCID-sp9u-9wwg-b7e9
31
vulnerability VCID-uc8j-r79v-n7ck
32
vulnerability VCID-uws5-j79f-cbar
33
vulnerability VCID-vz27-wyaf-tkcr
34
vulnerability VCID-w7f6-5b6h-8kh4
35
vulnerability VCID-wqyp-93bk-vbh2
36
vulnerability VCID-x5jd-qddc-eudq
37
vulnerability VCID-xap5-djda-2uem
38
vulnerability VCID-y71t-sfb1-w3gw
39
vulnerability VCID-zjx8-ydmt-juf3
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.2.15-1~bpo70%252B1
3
url pkg:deb/debian/gnutls28@3.2.15-2~bpo70%2B1
purl pkg:deb/debian/gnutls28@3.2.15-2~bpo70%2B1
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-334s-gdq8-jucy
1
vulnerability VCID-3qcs-1fcj-m3fw
2
vulnerability VCID-4f3z-x697-abd5
3
vulnerability VCID-5aea-cjz1-jkh1
4
vulnerability VCID-6fzu-8998-abdk
5
vulnerability VCID-6u4f-wt5u-8ueb
6
vulnerability VCID-86j1-j381-cucy
7
vulnerability VCID-92x9-x1ep-cqdn
8
vulnerability VCID-9pdw-udwq-6kbz
9
vulnerability VCID-a18u-4j99-nbf8
10
vulnerability VCID-a296-a2f2-kfba
11
vulnerability VCID-abn3-2b4q-z7ga
12
vulnerability VCID-egeh-jk4m-sba8
13
vulnerability VCID-f5c7-jcd9-67hj
14
vulnerability VCID-fybd-zwbt-23ad
15
vulnerability VCID-gy9e-81rw-pug2
16
vulnerability VCID-hycu-7x87-jkcf
17
vulnerability VCID-jxjc-vjdc-1yfj
18
vulnerability VCID-k31b-6m7s-pffq
19
vulnerability VCID-k5vv-ts4z-j7g5
20
vulnerability VCID-m31f-a3pn-yyb4
21
vulnerability VCID-mtvm-zj2z-m7gf
22
vulnerability VCID-nce1-q8wc-s3ae
23
vulnerability VCID-pf5n-65mk-2ff3
24
vulnerability VCID-q3g5-4xaf-hudf
25
vulnerability VCID-qp8x-339r-pbhe
26
vulnerability VCID-qtsh-kn2d-h7cr
27
vulnerability VCID-qup9-qy11-fqhe
28
vulnerability VCID-r531-qbtt-akgf
29
vulnerability VCID-sp9u-9wwg-b7e9
30
vulnerability VCID-uc8j-r79v-n7ck
31
vulnerability VCID-uws5-j79f-cbar
32
vulnerability VCID-vz27-wyaf-tkcr
33
vulnerability VCID-w7f6-5b6h-8kh4
34
vulnerability VCID-wqyp-93bk-vbh2
35
vulnerability VCID-x5jd-qddc-eudq
36
vulnerability VCID-xap5-djda-2uem
37
vulnerability VCID-y71t-sfb1-w3gw
38
vulnerability VCID-zjx8-ydmt-juf3
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.2.15-2~bpo70%252B1
4
url pkg:deb/debian/gnutls28@3.3.8-6~bpo70%2B1
purl pkg:deb/debian/gnutls28@3.3.8-6~bpo70%2B1
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-334s-gdq8-jucy
1
vulnerability VCID-3qcs-1fcj-m3fw
2
vulnerability VCID-4f3z-x697-abd5
3
vulnerability VCID-5aea-cjz1-jkh1
4
vulnerability VCID-6fzu-8998-abdk
5
vulnerability VCID-6u4f-wt5u-8ueb
6
vulnerability VCID-86j1-j381-cucy
7
vulnerability VCID-92x9-x1ep-cqdn
8
vulnerability VCID-9pdw-udwq-6kbz
9
vulnerability VCID-a18u-4j99-nbf8
10
vulnerability VCID-a296-a2f2-kfba
11
vulnerability VCID-abn3-2b4q-z7ga
12
vulnerability VCID-egeh-jk4m-sba8
13
vulnerability VCID-f5c7-jcd9-67hj
14
vulnerability VCID-fybd-zwbt-23ad
15
vulnerability VCID-gy9e-81rw-pug2
16
vulnerability VCID-jxjc-vjdc-1yfj
17
vulnerability VCID-k31b-6m7s-pffq
18
vulnerability VCID-k5vv-ts4z-j7g5
19
vulnerability VCID-m31f-a3pn-yyb4
20
vulnerability VCID-mtvm-zj2z-m7gf
21
vulnerability VCID-nce1-q8wc-s3ae
22
vulnerability VCID-pf5n-65mk-2ff3
23
vulnerability VCID-q3g5-4xaf-hudf
24
vulnerability VCID-qp8x-339r-pbhe
25
vulnerability VCID-qtsh-kn2d-h7cr
26
vulnerability VCID-qup9-qy11-fqhe
27
vulnerability VCID-r531-qbtt-akgf
28
vulnerability VCID-sp9u-9wwg-b7e9
29
vulnerability VCID-uc8j-r79v-n7ck
30
vulnerability VCID-uws5-j79f-cbar
31
vulnerability VCID-vz27-wyaf-tkcr
32
vulnerability VCID-w7f6-5b6h-8kh4
33
vulnerability VCID-wqyp-93bk-vbh2
34
vulnerability VCID-x5jd-qddc-eudq
35
vulnerability VCID-y71t-sfb1-w3gw
36
vulnerability VCID-zjx8-ydmt-juf3
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.3.8-6~bpo70%252B1
5
url pkg:deb/debian/gnutls28@3.3.8-6
purl pkg:deb/debian/gnutls28@3.3.8-6
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-334s-gdq8-jucy
1
vulnerability VCID-3qcs-1fcj-m3fw
2
vulnerability VCID-4f3z-x697-abd5
3
vulnerability VCID-5aea-cjz1-jkh1
4
vulnerability VCID-6fzu-8998-abdk
5
vulnerability VCID-6u4f-wt5u-8ueb
6
vulnerability VCID-86j1-j381-cucy
7
vulnerability VCID-92x9-x1ep-cqdn
8
vulnerability VCID-9pdw-udwq-6kbz
9
vulnerability VCID-a18u-4j99-nbf8
10
vulnerability VCID-a296-a2f2-kfba
11
vulnerability VCID-abn3-2b4q-z7ga
12
vulnerability VCID-egeh-jk4m-sba8
13
vulnerability VCID-f5c7-jcd9-67hj
14
vulnerability VCID-gy9e-81rw-pug2
15
vulnerability VCID-jxjc-vjdc-1yfj
16
vulnerability VCID-k31b-6m7s-pffq
17
vulnerability VCID-k5vv-ts4z-j7g5
18
vulnerability VCID-m31f-a3pn-yyb4
19
vulnerability VCID-mtvm-zj2z-m7gf
20
vulnerability VCID-nce1-q8wc-s3ae
21
vulnerability VCID-pf5n-65mk-2ff3
22
vulnerability VCID-q3g5-4xaf-hudf
23
vulnerability VCID-qp8x-339r-pbhe
24
vulnerability VCID-qtsh-kn2d-h7cr
25
vulnerability VCID-qup9-qy11-fqhe
26
vulnerability VCID-r531-qbtt-akgf
27
vulnerability VCID-sp9u-9wwg-b7e9
28
vulnerability VCID-uc8j-r79v-n7ck
29
vulnerability VCID-uws5-j79f-cbar
30
vulnerability VCID-vz27-wyaf-tkcr
31
vulnerability VCID-w7f6-5b6h-8kh4
32
vulnerability VCID-wqyp-93bk-vbh2
33
vulnerability VCID-x5jd-qddc-eudq
34
vulnerability VCID-y71t-sfb1-w3gw
35
vulnerability VCID-zjx8-ydmt-juf3
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.3.8-6
6
url pkg:deb/debian/gnutls28@3.3.8-6%2Bdeb8u7
purl pkg:deb/debian/gnutls28@3.3.8-6%2Bdeb8u7
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-334s-gdq8-jucy
1
vulnerability VCID-3qcs-1fcj-m3fw
2
vulnerability VCID-4f3z-x697-abd5
3
vulnerability VCID-5aea-cjz1-jkh1
4
vulnerability VCID-6fzu-8998-abdk
5
vulnerability VCID-6u4f-wt5u-8ueb
6
vulnerability VCID-86j1-j381-cucy
7
vulnerability VCID-92x9-x1ep-cqdn
8
vulnerability VCID-9pdw-udwq-6kbz
9
vulnerability VCID-a18u-4j99-nbf8
10
vulnerability VCID-a296-a2f2-kfba
11
vulnerability VCID-abn3-2b4q-z7ga
12
vulnerability VCID-egeh-jk4m-sba8
13
vulnerability VCID-f5c7-jcd9-67hj
14
vulnerability VCID-gy9e-81rw-pug2
15
vulnerability VCID-jxjc-vjdc-1yfj
16
vulnerability VCID-k31b-6m7s-pffq
17
vulnerability VCID-k5vv-ts4z-j7g5
18
vulnerability VCID-m31f-a3pn-yyb4
19
vulnerability VCID-mtvm-zj2z-m7gf
20
vulnerability VCID-nce1-q8wc-s3ae
21
vulnerability VCID-pf5n-65mk-2ff3
22
vulnerability VCID-q3g5-4xaf-hudf
23
vulnerability VCID-qp8x-339r-pbhe
24
vulnerability VCID-qtsh-kn2d-h7cr
25
vulnerability VCID-qup9-qy11-fqhe
26
vulnerability VCID-r531-qbtt-akgf
27
vulnerability VCID-sp9u-9wwg-b7e9
28
vulnerability VCID-uc8j-r79v-n7ck
29
vulnerability VCID-uws5-j79f-cbar
30
vulnerability VCID-vz27-wyaf-tkcr
31
vulnerability VCID-w7f6-5b6h-8kh4
32
vulnerability VCID-wqyp-93bk-vbh2
33
vulnerability VCID-x5jd-qddc-eudq
34
vulnerability VCID-y71t-sfb1-w3gw
35
vulnerability VCID-zjx8-ydmt-juf3
resource_url http://public2.vulnerablecode.io/packages/pkg:deb/debian/gnutls28@3.3.8-6%252Bdeb8u7
7
url pkg:rpm/redhat/gnutls@3.3.26-9?arch=el7
purl pkg:rpm/redhat/gnutls@3.3.26-9?arch=el7
is_vulnerable true
affected_by_vulnerabilities
0
vulnerability VCID-4f3z-x697-abd5
1
vulnerability VCID-6u4f-wt5u-8ueb
2
vulnerability VCID-egeh-jk4m-sba8
3
vulnerability VCID-k31b-6m7s-pffq
4
vulnerability VCID-m31f-a3pn-yyb4
5
vulnerability VCID-mtvm-zj2z-m7gf
6
vulnerability VCID-y71t-sfb1-w3gw
resource_url http://public2.vulnerablecode.io/packages/pkg:rpm/redhat/gnutls@3.3.26-9%3Farch=el7
References
0
reference_url https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2016-7444.json
reference_id
reference_type
scores
0
value 5.3
scoring_system cvssv3
scoring_elements CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
url https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2016-7444.json
1
reference_url https://api.first.org/data/v1/epss?cve=CVE-2016-7444
reference_id
reference_type
scores
0
value 0.01021
scoring_system epss
scoring_elements 0.77173
published_at 2026-04-01T12:55:00Z
1
value 0.01021
scoring_system epss
scoring_elements 0.77273
published_at 2026-04-16T12:55:00Z
2
value 0.01021
scoring_system epss
scoring_elements 0.77258
published_at 2026-04-11T12:55:00Z
3
value 0.01021
scoring_system epss
scoring_elements 0.77237
published_at 2026-04-12T12:55:00Z
4
value 0.01021
scoring_system epss
scoring_elements 0.77233
published_at 2026-04-13T12:55:00Z
5
value 0.01021
scoring_system epss
scoring_elements 0.77179
published_at 2026-04-02T12:55:00Z
6
value 0.01021
scoring_system epss
scoring_elements 0.77208
published_at 2026-04-04T12:55:00Z
7
value 0.01021
scoring_system epss
scoring_elements 0.77189
published_at 2026-04-07T12:55:00Z
8
value 0.01021
scoring_system epss
scoring_elements 0.77221
published_at 2026-04-08T12:55:00Z
9
value 0.01021
scoring_system epss
scoring_elements 0.7723
published_at 2026-04-09T12:55:00Z
url https://api.first.org/data/v1/epss?cve=CVE-2016-7444
2
reference_url https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7444
reference_id
reference_type
scores
url https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7444
3
reference_url https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
reference_id
reference_type
scores
0
value 4.3
scoring_system cvssv2
scoring_elements AV:N/AC:M/Au:N/C:N/I:P/A:N
url https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
4
reference_url https://bugzilla.redhat.com/show_bug.cgi?id=1374266
reference_id 1374266
reference_type
scores
url https://bugzilla.redhat.com/show_bug.cgi?id=1374266
5
reference_url https://security.archlinux.org/ASA-201609-25
reference_id ASA-201609-25
reference_type
scores
url https://security.archlinux.org/ASA-201609-25
6
reference_url https://security.archlinux.org/ASA-201609-26
reference_id ASA-201609-26
reference_type
scores
url https://security.archlinux.org/ASA-201609-26
7
reference_url https://security.archlinux.org/AVG-17
reference_id AVG-17
reference_type
scores
0
value Medium
scoring_system archlinux
scoring_elements
url https://security.archlinux.org/AVG-17
8
reference_url https://security.archlinux.org/AVG-26
reference_id AVG-26
reference_type
scores
0
value Medium
scoring_system archlinux
scoring_elements
url https://security.archlinux.org/AVG-26
9
reference_url https://access.redhat.com/errata/RHSA-2017:2292
reference_id RHSA-2017:2292
reference_type
scores
url https://access.redhat.com/errata/RHSA-2017:2292
10
reference_url https://usn.ubuntu.com/3183-1/
reference_id USN-3183-1
reference_type
scores
url https://usn.ubuntu.com/3183-1/
Weaknesses
0
cwe_id 295
name Improper Certificate Validation
description The product does not validate, or incorrectly validates, a certificate.
Exploits
Severity_range_score4.0 - 6.9
Exploitability0.5
Weighted_severity6.2
Risk_score3.1
Resource_urlhttp://public2.vulnerablecode.io/vulnerabilities/VCID-6u4f-wt5u-8ueb