FCGI versions 0.44 through 0.82, for Perl, include a vulnerable version of the FastCGI fcgi2 (aka fcgi) library
Noroxi assessment
Priority: Monitor (action score 21/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.67% (FIRST EPSS); higher than 51.1% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: perl-FCGI (AlmaLinux:10) 1:0.82-13.1.el10_0; perl-FCGI (AlmaLinux:8) 1:0.78-12.module_el8.10.0+4013+e6a7e623, 1:0.78-12.module_el8.10.0+4011+62915be2, 1:0.78-12.module_el8.10.0+4012+cd64a238; perl-FCGI (AlmaLinux:9) 1:0.79-8.1.el9_6.
Low priority for now. Upgrade to perl-FCGI (AlmaLinux:10) 1:0.82-13.1.el10_0; perl-FCGI (AlmaLinux:8) 1:0.78-12.module_el8.10.0+4013+e6a7e623, 1:0.78-12.module_el8.10.0+4011+62915be2, 1:0.78-12.module_el8.10.0+4012+cd64a238; perl-FCGI (AlmaLinux:9) 1:0.79-8.1.el9_6 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
FCGI versions 0.44 through 0.82, for Perl, include a vulnerable version of the FastCGI fcgi2 (aka fcgi) library. The included FastCGI library is affected by CVE-2025-23016, causing an integer overflow (and resultant heap-based buffer overflow) via crafted nameLen or valueLen values in data to the IPC socket. This occurs in ReadParams in fcgiapp.c.
- Published
- May 16, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.7% · 51th percentile
- CWE
- CWE-122
Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.7%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| fastcgi | fcgi | cpe:2.3:a:fastcgi:fcgi |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- fastcgi fcgi0.44 and later · up to 0.82 inclusive
Versions reported by the vendor
Affected version ranges reported by the assigning authority (CPANSec). Independent of NVD's CPE analysis and usually ahead of it.
ETHER FCGI
- 0.44 and later · up to and including 0.82affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | perl-FCGI | before 1:0.82-13.1.el10_0 | 1:0.82-13.1.el10_0 |
| AlmaLinux:8 | perl-FCGI | before 1:0.78-12.module_el8.10.0+4013+e6a7e623 | 1:0.78-12.module_el8.10.0+4013+e6a7e623 |
| AlmaLinux:8 | perl-FCGI | before 1:0.78-12.module_el8.10.0+4011+62915be2 | 1:0.78-12.module_el8.10.0+4011+62915be2 |
| AlmaLinux:8 | perl-FCGI | before 1:0.78-12.module_el8.10.0+4012+cd64a238 | 1:0.78-12.module_el8.10.0+4012+cd64a238 |
| AlmaLinux:9 | perl-FCGI | before 1:0.79-8.1.el9_6 | 1:0.79-8.1.el9_6 |
| Debian:12 | libfcgi-perl | before 0.79+ds-2 | 0.79+ds-2 |
| Red Hat:enterprise_linux:10.0 | perl-FCGI | before 1:0.82-13.1.el10_0 | 1:0.82-13.1.el10_0 |
| Red Hat:enterprise_linux:10.0 | perl-FCGI-debuginfo | before 1:0.82-13.1.el10_0 | 1:0.82-13.1.el10_0 |
| Red Hat:enterprise_linux:10.0 | perl-FCGI-debugsource | before 1:0.82-13.1.el10_0 | 1:0.82-13.1.el10_0 |
| Red Hat:enterprise_linux:8::appstream | perl-FCGI | before 1:0.78-12.module+el8.10.0+23147+df114ff4 | 1:0.78-12.module+el8.10.0+23147+df114ff4 |
| Red Hat:enterprise_linux:8::appstream | perl-FCGI-debuginfo | before 1:0.78-12.module+el8.10.0+23147+df114ff4 | 1:0.78-12.module+el8.10.0+23147+df114ff4 |
| Red Hat:enterprise_linux:8::appstream | perl-FCGI-debugsource | before 1:0.78-12.module+el8.10.0+23147+df114ff4 | 1:0.78-12.module+el8.10.0+23147+df114ff4 |
| Red Hat:enterprise_linux:9::appstream | perl-FCGI | before 1:0.79-8.1.el9_6 | 1:0.79-8.1.el9_6 |
| Red Hat:enterprise_linux:9::appstream | perl-FCGI-debuginfo | before 1:0.79-8.1.el9_6 | 1:0.79-8.1.el9_6 |
| Red Hat:enterprise_linux:9::appstream | perl-FCGI-debugsource | before 1:0.79-8.1.el9_6 | 1:0.79-8.1.el9_6 |
| Red Hat:rhel_aus:8.2::appstream | perl-FCGI | before 1:0.78-11.module+el8.2.0+23234+edafdda3.1 | 1:0.78-11.module+el8.2.0+23234+edafdda3.1 |
| Red Hat:rhel_aus:8.2::appstream | perl-FCGI-debuginfo | before 1:0.78-11.module+el8.2.0+23234+edafdda3.1 | 1:0.78-11.module+el8.2.0+23234+edafdda3.1 |
| Red Hat:rhel_aus:8.2::appstream | perl-FCGI-debugsource | before 1:0.78-11.module+el8.2.0+23234+edafdda3.1 | 1:0.78-11.module+el8.2.0+23234+edafdda3.1 |
| Red Hat:rhel_aus:8.4::appstream | perl-FCGI | before 1:0.78-11.module+el8.4.0+23229+35c4aba7.1 | 1:0.78-11.module+el8.4.0+23229+35c4aba7.1 |
| Red Hat:rhel_aus:8.4::appstream | perl-FCGI-debuginfo | before 1:0.78-11.module+el8.4.0+23229+35c4aba7.1 | 1:0.78-11.module+el8.4.0+23229+35c4aba7.1 |
| Red Hat:rhel_aus:8.4::appstream | perl-FCGI-debugsource | before 1:0.78-11.module+el8.4.0+23229+35c4aba7.1 | 1:0.78-11.module+el8.4.0+23229+35c4aba7.1 |
| Red Hat:rhel_aus:8.6::appstream | perl-FCGI | before 1:0.78-11.module+el8.6.0+23193+c3786137.1 | 1:0.78-11.module+el8.6.0+23193+c3786137.1 |
| Red Hat:rhel_aus:8.6::appstream | perl-FCGI-debuginfo | before 1:0.78-11.module+el8.6.0+23193+c3786137.1 | 1:0.78-11.module+el8.6.0+23193+c3786137.1 |
| Red Hat:rhel_aus:8.6::appstream | perl-FCGI-debugsource | before 1:0.78-11.module+el8.6.0+23193+c3786137.1 | 1:0.78-11.module+el8.6.0+23193+c3786137.1 |
+20
Same product
fastcgi: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-23016FastCGI fcgi2 (aka fcgi) 2.x through 2.4.4 has an integer overflow (and resultant heap-based buffer overflow) via crafted nameLen or valueLe37Monitor
- CVE-2012-6687FastCGI (aka fcgi and libfcgi) 2.4.0 allows remote attackers to cause a denial of service (segmentation fault and crash) via a large number 22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:perl-FCGI | 1:0.79-8.1.el9_6 · AlmaLinux:9 | Package registry (OSV) |
| debian:libfcgi-perl | 0.79+ds-2 · Debian:12 | Package registry (OSV) |
| red hat:perl-FCGI | 1:0.74-8.el7_9.1 · Red Hat:rhel_els:7 | Package registry (OSV) |
| red hat:perl-FCGI-debuginfo | 1:0.74-8.el7_9.1 · Red Hat:rhel_els:7 | Package registry (OSV) |
| red hat:perl-FCGI-debugsource | 1:0.79-8.1.el9_6 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| rocky linux:perl-FCGI | 1:0.79-8.1.el9_6 · Rocky Linux:9 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Synacktivfinder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- Low
Weakness class (CWE)
CWE-122 · Heap-based Buffer OverflowCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.