CVE-2023-39325 | HTTP/2 rapid reset can cause excessive work in net/http

A malicious HTTP/2 client which rapidly creates requests and immediately resets them can cause excessive server resource consumption. While the total number of requests is bounded by the http2.Server.MaxConcurrentStreams setting, resetting an in-progress request allows the attacker to create a new request while the existing one is still executing. With the fix applied, HTTP/2 servers now bound the number of simultaneously executing handler goroutines to the stream concurrency limit (MaxConcurrentStreams). New requests arriving when at the limit (which can only happen after the client has reset an existing, in-flight request) will be queued until a handler exits. If the request queue grows too large, the server will terminate the connection. This issue is also fixed in golang.org/x/net/http2 for users manually configuring HTTP/2. The default stream concurrency limit is 250 streams (requests) per HTTP/2 connection. This value may be adjusted using the golang.org/x/net/http2 package; see the Server.MaxConcurrentStreams setting and the ConfigureServer function.

Published: 2023-10-11 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-39325 is rated Moderate Risk (64.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.80%). Core evidence: EPSS rose +3.65% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.

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-2023-39325

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 2026-06-15 0.15% 3.80% +3.65%
2 2026-03-04 0.09% 0.15% +0.06%
3 2026-03-01 0.09%

Full EPSS history (44 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-39325

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-39325

GitHub Security Advisory for CVE-2023-39325

GHSA-4374-p667-p6c8 · Severity: high · Ecosystem: go — HTTP/2 rapid reset can cause excessive work in net/http

OS Trackers for CVE-2023-39325

vendor priority summary link
alpine CVE-2023-39325: 1 source package rows (go); 30 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 6, open 24. https://security.alpinelinux.org/vuln/CVE-2023-39325
debian not yet assigned CVE-2023-39325 not yet assigned priority: Debian including 2 source packages (golang-1.15, golang-1.19), 2 status rows across 2 suites (bookworm, bullseye): open 2. https://security-tracker.debian.org/tracker/CVE-2023-39325
gentoo high CVE-2023-39325: 1 GLSA(s) (202311-09), 1 atom(s) (dev-lang/go); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-39325
redhat high https://access.redhat.com/security/cve/CVE-2023-39325
suse high CVE-2023-39325 severity important: SUSE including 206 source package names (1.21-2.34.5:go1.21-1.21.3-150000.1.12.1, 1.21-2.34.5:go1.21-doc-1.21.3-150000.1.12.1, …), 911 product×package rows across 80 product lines (Container bci/golang, Container suse/kubectl, … (80 product lines)): Known Not Affected 538, Fixed 337, Will Not Fix 36. https://www.suse.com/security/cve/CVE-2023-39325/
ubuntu medium CVE-2023-39325 medium priority: Ubuntu including 13 source packages (golang, golang-1.10, …), 156 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 106, needs-triage 24, released 15, ignored 10, not-affected 1. https://ubuntu.com/security/CVE-2023-39325

Affected software / configurations for CVE-2023-39325

Vendor Product Version Raw CPE
golang go >= 1.20.0, < 1.20.10 cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
golang go >= 1.21.0, < 1.21.3 cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
golang http2 < 0.17.0 cpe:2.3:a:golang:http2:*:*:*:*:*:go:*:*
fedoraproject fedora 37 cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*
fedoraproject fedora 38 cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*
fedoraproject fedora 39 cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:*
netapp astra_trident cpe:2.3:a:netapp:astra_trident:-:*:*:*:*:*:*:*
netapp astra_trident_autosupport cpe:2.3:a:netapp:astra_trident_autosupport:-:*:*:*:*:*:*:*

References for CVE-2023-39325

URL Tags
https://go.dev/cl/534215 Vendor Advisory
https://go.dev/cl/534235 Vendor Advisory
https://go.dev/issue/63417 Issue Tracking Vendor Advisory
https://groups.google.com/g/golang-announce/c/iNNxDTCjZvo/m/UDd7VKQuAAAJ Release Notes
https://lists.fedoraproject.org/archives/list/[email protected]/message/3OVW5V2DM5K5IC3H7O42YDUGNJ74J35O/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/3SZN67IL7HMGMNAVLOTIXLIHUDXZK4LH/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/3WJ4QVX2AMUJ2F2S27POOAHRC4K3CHU4/
https://lists.fedoraproject.org/archives/list/[email protected]/message/4BUK2ZIAGCULOOYDNH25JPU6JBES5NF2/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/5RSKA2II6QTD4YUKUNDVJQSRYSFC4VFR/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/AVZDNSMVDAQJ64LJC5I5U5LDM5753647/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/CHHITS4PUOZAKFIUBQAQZC7JWXMOYE4B/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/CLB4TW7KALB3EEQWNWCN7OUIWWVWWCG2/ Mailing List
https://lists.fedoraproject.org/archives/list/[email protected]/message/D2BBIDR2ZMB3X5BC7SR4SLQMHRMVPY6L/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/ECRC75BQJP6FJN2L7KCKYZW4DSBD7QSD/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/FTMJ3NJIDAZFWJQQSP3L22MUFJ3UP2PT/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/GSY7SXFFTPZFWDM6XELSDSHZLVW3AHK7/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/HZQIELEIRSZUYTFFH5KTH2YJ4IIQG2KE/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/IPWCNYB5PQ5PCVZ4NJT6G56ZYFZ5QBU6/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/KEOTKBUPZXHE3F352JBYNTSNRXYLWD6P/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/KSEGD2IWKNUO3DWY4KQGUQM5BISRWHQE/ Mailing List
https://lists.fedoraproject.org/archives/list/[email protected]/message/L5E5JSJBZLYXOTZWXHJKRVCIXIHVWKJ6/
https://lists.fedoraproject.org/archives/list/[email protected]/message/MZQYOOKHQDQ57LV2IAG6NRFOVXKHJJ3Z/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/NG7IMPL55MVWU3LCI4JQJT3K2U5CHDV7/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/ODBY7RVMGZCBSTWF2OZGIZS57FNFUL67/
https://lists.fedoraproject.org/archives/list/[email protected]/message/OXGWPQOJ3JNDW2XIYKIVJ7N7QUIFNM2Q/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/PJCUNGIQDUMZ4Z6HWVYIMR66A35F5S74/
https://lists.fedoraproject.org/archives/list/[email protected]/message/QF5QSYAOPDOWLY6DUHID56Q4HQFYB45I/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/QXOU2JZUBEBP7GBKAYIJRPRBZSJCD7ST/
https://lists.fedoraproject.org/archives/list/[email protected]/message/R3UETKPUB3V5JS5TLZOF3SMTGT5K5APS/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/REMHVVIBDNKSRKNOTV7EQSB7CYQWOUOU/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/T7N5GV4CHH6WAGX3GFMDD3COEOVCZ4RI/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/ULQQONMSCQSH5Z5OWFFQHCGEZ3NL4DRJ/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/UTT7DG3QOF5ZNJLUGHDNLRUIN6OWZARP/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/W2LZSWTV4NV4SNQARNXG5T6LRHP26EW2/
https://lists.fedoraproject.org/archives/list/[email protected]/message/WCNCBYKZXLDFGAJUB7ZP5VLC3YTHJNVH/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/XFOIBB4YFICHDM7IBOP7PWXW3FX4HLL2/ Mailing List
https://lists.fedoraproject.org/archives/list/[email protected]/message/XTNLSL44Y5FB6JWADSZH6DCV4JJAAEQY/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/YJWHBLVZDM5KQSDFRBFRKU5KSSOLIRQ4/
https://lists.fedoraproject.org/archives/list/[email protected]/message/YRKEXKANQ7BKJW2YTAMP625LJUJZLJ4P/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/ZSVEMQV5ROY5YW5QE3I57HT3ITWG5GCV/ Mailing List Third Party Advisory
https://pkg.go.dev/vuln/GO-2023-2102 Vendor Advisory
https://security.gentoo.org/glsa/202311-09 Mailing List Third Party Advisory
https://security.netapp.com/advisory/ntap-20231110-0008/ Third Party Advisory
cvelogic Threat Intelligence